Table of Contents
- About this manual
- Chapter 1. Safety information
- Chapter 2. Important service information
- Chapter 3. General checkout
- Chapter 4. Related service information
- Chapter 5. Special keys
- Chapter 6. Locations
- Chapter 7. FRU replacement notices
- Chapter 8. Removing or replacing a FRU
- General guidelines
- Disabling the built-in battery
- 1010 MicroSD card
- 1020 ThinkPad Pen Pro
- 1030 Keyboard
- 1030 Base cover assembly
- 1040 Memory module
- 1060 M.2 solid-state drive
- 1070 Coin-cell battery
- 1080 Wireless LAN card
- 1090 Battery
- 1100 Speaker assembly
- 1110 Trackpad and trackpad cable
- 1120 Wireless LAN antenna assembly
- 1130 ThinkPad Pen Pro charger with cable
- 1140 Power button board with cable
- 1150 NFC board with cable, NFC attenna
- 1160 Fingerprint reader bracket and fingerprint reader with cable
- 1170 Rear camera board with cable
- 1180 LCD unit
- 1190 HDMI connector bracket
- 1200 USB 3.1 connector bracket
- 1210 Thermal fan
- 1220 System board
- 1230 Keyboard bezel assembly
- LCD FRUs for Yoga models
- LCD FRUs for non-yoga models
- Appendix A. Notices
- Appendix B. Abbreviation and acronym table
Lenovo L390 User Manual
Displayed below is the user manual for L390 by Lenovo which is a product in the Notebooks category. This manual has pages.
Related Manuals
L390, L390 Yoga, S2 4th Gen, and S2 Yoga
4th Gen
Hardware Maintenance Manual
Note: Before using this information and the product it supports, be sure to read the general information
under Appendix A “Notices” on page 107.
First Edition (December 2018)
© Copyright Lenovo 2018.
LIMITED AND RESTRICTED RIGHTS NOTICE: If data or software is delivered pursuant a General Services Administration
“GSA” contract, use, reproduction, or disclosure is subject to restrictions set forth in Contract No. GS-35F-05925.
Contents
About this manual . . . . . . . . . . . . iii
Chapter 1. Safety information . . . . . . 1
General safety . . . . . . . . . . . . . . . . 1
Electrical safety . . . . . . . . . . . . . . . . 1
Safety inspection guide . . . . . . . . . . . . . 3
Handling devices that are sensitive to electrostatic
discharge . . . . . . . . . . . . . . . . . . 3
Grounding requirements . . . . . . . . . . . . 4
Safety notices (multilingual translations) . . . . . . 4
Chapter 2. Important service
information . . . . . . . . . . . . . . . 21
Strategy for replacing FRUs . . . . . . . . . . 21
Strategy for replacing a hard disk drive or a
solid-state drive . . . . . . . . . . . . . 21
Important notice for replacing a system
board . . . . . . . . . . . . . . . . . 22
How to use error codes . . . . . . . . . . 22
Strategy for replacing FRUs for CTO, special-bid,
and standard models. . . . . . . . . . . . . 22
Product definition . . . . . . . . . . . . 22
FRU identification. . . . . . . . . . . . 23
Chapter 3. General checkout . . . . . 25
What to do first . . . . . . . . . . . . . . . 25
Checkout guide . . . . . . . . . . . . . . . 26
Diagnosing problems . . . . . . . . . . . 26
Quick test programs . . . . . . . . . . . 27
UEFI diagnostic program . . . . . . . . . 27
Bootable diagnostic programs . . . . . . . 28
Power system checkout . . . . . . . . . . . 28
Checking the ac power adapter . . . . . . . 29
Checking operational charging . . . . . . . 29
Checking the battery pack . . . . . . . . . 29
Checking the coin-cell battery . . . . . . . 30
Chapter 4. Related service
information . . . . . . . . . . . . . . . 31
Recovery overview for the Windows 10 operating
system . . . . . . . . . . . . . . . . . . 31
Resetting your computer . . . . . . . . . 31
Using advanced startup options . . . . . . 31
Recovering your operating system if Windows
10 fails to start . . . . . . . . . . . . . 32
Creating and using a recovery USB drive . . . 32
Passwords. . . . . . . . . . . . . . . . . 32
Power-on password . . . . . . . . . . . 33
Hard disk password . . . . . . . . . . . 33
Supervisor password . . . . . . . . . . . 33
How to remove the power-on password . . . 33
How to remove the hard disk password. . . . 34
Power management . . . . . . . . . . . . . 34
Sleep mode . . . . . . . . . . . . . . 34
Hibernation mode . . . . . . . . . . . . 35
Symptom-to-FRU index . . . . . . . . . . . 35
Numeric error codes . . . . . . . . . . . 36
Error messages . . . . . . . . . . . . . 38
Beep errors. . . . . . . . . . . . . . . 38
No-beep symptoms . . . . . . . . . . . 39
LCD-related symptoms . . . . . . . . . . 40
Intermittent problems . . . . . . . . . . . 40
Undetermined problems . . . . . . . . . 41
Chapter 5. Special keys . . . . . . . . 43
Chapter 6. Locations . . . . . . . . . 45
Locating computer controls, connectors, and
indicators . . . . . . . . . . . . . . . . . 45
Front . . . . . . . . . . . . . . . . . 45
Base . . . . . . . . . . . . . . . . . 46
Left-side view . . . . . . . . . . . . . . 46
Right-side view . . . . . . . . . . . . . 47
Bottom view . . . . . . . . . . . . . . 47
Locating FRUs and CRUs . . . . . . . . . . . 47
Major FRUs and CRUs . . . . . . . . . . 49
LCD FRUs and CRUs . . . . . . . . . . . 51
Miscellaneous parts . . . . . . . . . . . 54
Connector and cable guide . . . . . . . . 54
Looking up FRU information . . . . . . . . . . 60
Chapter 7. FRU replacement
notices . . . . . . . . . . . . . . . . . 61
Service tool kit . . . . . . . . . . . . . . . 61
Screw notices . . . . . . . . . . . . . . . 62
Retaining serial numbers . . . . . . . . . . . 62
Restoring the serial number of the system
unit . . . . . . . . . . . . . . . . . . 63
Retaining the UUID. . . . . . . . . . . . 63
Chapter 8. Removing or replacing a
FRU. . . . . . . . . . . . . . . . . . . 65
General guidelines. . . . . . . . . . . . . . 65
Disabling the built-in battery . . . . . . . . . . 66
1010 MicroSD card . . . . . . . . . . . . . 66
1020 ThinkPad Pen Pro. . . . . . . . . . . . 67
1030 Keyboard . . . . . . . . . . . . . . . 67
© Copyright Lenovo 2018 i
1030 Base cover assembly . . . . . . . . . . 69
1040 Memory module . . . . . . . . . . . . 71
1060 M.2 solid-state drive . . . . . . . . . . . 71
1070 Coin-cell battery . . . . . . . . . . . . 73
1080 Wireless LAN card . . . . . . . . . . . 74
1090 Battery . . . . . . . . . . . . . . . . 75
1100 Speaker assembly . . . . . . . . . . . 76
1110 Trackpad and trackpad cable . . . . . . . 77
1120 Wireless LAN antenna assembly . . . . . . 78
1130 ThinkPad Pen Pro charger with cable . . . . 80
1140 Power button board with cable . . . . . . 81
1150 NFC board with cable, NFC attenna . . . . 82
1160 Fingerprint reader bracket and fingerprint
reader with cable . . . . . . . . . . . . . . 83
1170 Rear camera board with cable . . . . . . . 84
1180 LCD unit . . . . . . . . . . . . . . . 85
1190 HDMI connector bracket . . . . . . . . . 87
1200 USB 3.1 connector bracket . . . . . . . . 88
1210 Thermal fan . . . . . . . . . . . . . . 88
1220 System board . . . . . . . . . . . . . 90
1230 Keyboard bezel assembly . . . . . . . . 93
LCD FRUs for Yoga models . . . . . . . . . . 93
2010 Strip cover and rubber caps . . . . . . 94
2020 Touch module assembly and hinge
rubber. . . . . . . . . . . . . . . . . 94
2030 LCD hinges . . . . . . . . . . . . 96
2040 LCD cable and touch control board . . . 97
2050 Infrared camera/microphone module
with cable . . . . . . . . . . . . . . . 98
2060 Sensor board with cable and LCD rear
cover assembly . . . . . . . . . . . . . 100
2070 ThinkPad-logo-LED card with cable . . . 102
LCD FRUs for non-yoga models . . . . . . . . 102
2080 LCD bezel . . . . . . . . . . . . . 102
2090 LCD panel and LCD cable . . . . . . 103
2100 LCD hinges . . . . . . . . . . . . 104
2110 RGB camera/microphone module with
cable and LCD rear cover assembly . . . . . 105
Appendix A. Notices . . . . . . . . . . 107
Appendix B. Abbreviation and
acronym table . . . . . . . . . . . . . 109
ii L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
About this manual
This manual contains service and reference information for the following ThinkPad® product:
ThinkPad L390 Yoga Machine types: 20NT, 20NU
ThinkPad L390 Machine types: 20NR, 20NS
ThinkPad S2 Yoga 4th Gen Machine type: 20NW
ThinkPad S2 4th Gen Machine type: 20NV
Use this manual along with the advanced diagnostic tests to troubleshoot problems.
Important:
This manual is intended only for trained service technicians who are familiar with ThinkPad products. Use
this manual along with the advanced diagnostic tests to troubleshoot problems effectively.
Before servicing a ThinkPad product, be sure to read all the information under Chapter 1 “Safety
information” on page 1 and Chapter 2 “Important service information” on page 21.
© Copyright Lenovo 2018 iii
iv L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Chapter 1. Safety information
This chapter presents the following safety information that you need to be familiar with before you service a
ThinkPad notebook computer.
• “General safety” on page 1
• “Electrical safety” on page 1
• “Safety inspection guide” on page 3
• “Handling devices that are sensitive to electrostatic discharge” on page 3
• “Grounding requirements” on page 4
• “Safety notices (multilingual translations)” on page 4
General safety
Follow these rules to ensure general safety:
• Observe good housekeeping in the area of the machines during and after maintenance.
• When lifting any heavy object:
1. Ensure that you can stand safely without slipping.
2. Distribute the weight of the object equally between your feet.
3. Use a slow lifting force. Never move suddenly or twist when you attempt to lift.
4. Lift by standing or by pushing up with your leg muscles; this action removes the strain from the
muscles in your back. Do not attempt to lift any object that weighs more than 16 kg (35 lb) or that you
think is too heavy for you.
• Do not perform any action that causes hazards to the customer, or that makes the equipment unsafe.
• Before you start the machine, ensure that other service technicians and the customer's personnel are not
in a hazardous position.
• Place removed covers and other parts in a safe place, away from all personnel, while you are servicing the
machine.
• Keep your toolcase away from walk areas so that other people will not trip over it.
• Do not wear loose clothing that can be trapped in the moving parts of a machine. Ensure that your sleeves
are fastened or rolled up above your elbows. If your hair is long, fasten it.
• Insert the ends of your necktie or scarf inside clothing or fasten it with a nonconductive clip, about 8
centimeters (3 inches) from the end.
• Do not wear jewelry, chains, metal-frame eyeglasses, or metal fasteners for your clothing, because metal
objects are good electrical conductors.
• Wear safety glasses when you are hammering, drilling, soldering, cutting wire, attaching springs, using
solvents, or working in any other conditions that might be hazardous to your eyes.
• After service, reinstall all safety shields, guards, labels, and ground wires. Replace any safety device that
is worn or defective.
• Reinstall all covers correctly before returning the machine to the customer.
• Fan louvers on the machine help to prevent overheating of internal components. Do not obstruct fan
louvers or cover them with labels or stickers.
Electrical safety
Observe the following rules when working on electrical equipment.
© Copyright Lenovo 2018 1
Important:
• Use only approved tools and test equipment. Some hand tools have handles covered with a soft material
that does not insulate you when working with live electrical currents.
• Many customers have, near their equipment, rubber floor mats that contain small conductive fibers to
decrease electrostatic discharges (ESD). Do not use this type of mat to protect yourself from electrical
shock.
• Find the room emergency power-off (EPO) switch, disconnecting switch, or electrical outlet. If an electrical
accident occurs, you can then operate the switch or unplug the power cord quickly.
• Do not work alone under hazardous conditions or near equipment that has hazardous voltages.
• Disconnect all power before:
– Performing a mechanical inspection
– Working near power supplies
– Removing or installing main units
• Before you start to work on the machine, unplug the power cord. If you cannot unplug it, ask the customer
to power off the wall box that supplies power to the machine, and to lock the wall box in the off position.
• If you need to work on a machine that has exposed electrical circuits, observe the following precautions:
– Ensure that another person, familiar with the power-off controls, is near you. That person must be there
to switch off the power, if necessary.
– Use only one hand when working with powered-on electrical equipment; keep the other hand in your
pocket or behind your back.
CAUTION:
An electrical shock can occur only when there is a complete circuit. By observing the above rule,
you may prevent a current from passing through your body.
– When using testers, set the controls correctly and use the approved probe leads and accessories for
that tester.
– Stand on suitable rubber mats (obtained locally, if necessary) to insulate you from grounds such as
metal floor strips and machine frames.
Observe the special safety precautions when you work with very high voltages. Instructions for these
precautions are in the safety sections of maintenance information. Use extreme care when measuring high
voltages.
• Regularly inspect and maintain your electrical hand tools for safe operational condition.
• Do not use worn or broken tools and testers.
• Never assume that power has been disconnected from a circuit. First, check that it has been powered off.
• Always look carefully for possible hazards in your work area. Examples of these hazards are moist floors,
nongrounded power extension cables, power surges, and missing safety grounds.
• Do not touch live electrical circuits with the reflective surface of a plastic dental mirror. The surface is
conductive; such touching can cause personal injury and machine damage.
• Do not service the following parts with the power on:
– Power supply units
– Pumps
– Blowers and fans
– Motor generators
– Units similar to those listed above
This practice ensures correct grounding of the units.
• If an electrical accident occurs:
– Use caution; do not become a victim yourself.
– Switch off power.
– Send another person to get medical aid.
2L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Safety inspection guide
The purpose of this inspection guide is to assist you in identifying potentially unsafe conditions. As each
machine was designed and built, required safety items were installed to protect users and service
technicians from injury. This guide addresses only those items. You should use good judgment to identify
potential safety hazards due to attachment of non-ThinkPad features or options not covered by this
inspection guide.
If any unsafe conditions are present, you must determine how serious the apparent hazard could be and
whether you can continue without first correcting the problem.
Consider these conditions and the safety hazards they present:
• Electrical hazards, especially primary power (primary voltage on the frame can cause serious or fatal
electrical shock)
• Explosive hazards, such as a damaged CRT face or a bulging capacitor
• Mechanical hazards, such as loose or missing hardware
To determine whether there are any potentially unsafe conditions, use the following checklist at the
beginning of every service task. Begin the checks with the power off, and the power cord disconnected.
Checklist:
1. Check exterior covers for damage (loose, broken, or sharp edges).
2. Turn off the computer. Disconnect the power cord.
3. Check the power cord for:
a. A third-wire ground connector in good condition. Use a meter to measure third-wire ground
continuity for 0.1 ohm or less between the external ground pin and the frame ground.
b. The power cord should be the authorized type specified for your computer. Go to: https://
support.lenovo.com/partslookup.
c. Insulation must not be frayed or worn.
4. Check for cracked or bulging batteries.
5. Remove the cover.
6. Check for any obvious non-ThinkPad alterations. Use good judgment as to the safety of any non-
ThinkPad alterations.
7. Check inside the unit for any obvious unsafe conditions, such as metal filings, contamination, water or
other liquids, or signs of fire or smoke damage.
8. Check for worn, frayed, or pinched cables.
9. Check that the power-supply cover fasteners (screws or rivets) have not been removed or tampered
with.
Handling devices that are sensitive to electrostatic discharge
Any computer part containing transistors or integrated circuits (ICs) should be considered sensitive to
electrostatic discharge (ESD). ESD damage can occur when there is a difference in charge between objects.
Protect against ESD damage by equalizing the charge so that the machine, the part, the work mat, and the
person handling the part are all at the same charge.
Notes:
1. Use product-specific ESD procedures when they exceed the requirements noted here.
Chapter 1.Safety information 3
2. Ensure that the ESD protective devices you use have been certified (ISO 9000) as fully effective.
When handling ESD-sensitive parts:
• Keep the parts in protective packages until they are inserted into the product.
• Avoid contact with other people.
• Wear a grounded wrist strap against your skin to eliminate static on your body.
• Prevent the part from touching your clothing. Most clothing is insulative and retains a charge even when
you are wearing a wrist strap.
• Use a grounded work mat to provide a static-free work surface. The mat is especially useful when
handling ESD-sensitive devices.
• Select a grounding system, such as those listed below, to provide protection that meets the specific
service requirement.
Note: The use of a grounding system to guard against ESD damage is desirable but not necessary.
– Attach the ESD ground clip to any frame ground, ground braid, or green-wire ground.
– When working on a double-insulated or battery-operated system, use an ESD common ground or
reference point. You can use coax or connector-outside shells on these systems.
– Use the round ground prong of the ac plug on ac-operated computers.
Grounding requirements
Electrical grounding of the computer is required for operator safety and correct system function. Proper
grounding of the electrical outlet can be verified by a certified electrician.
Safety notices (multilingual translations)
The safety notices in this section are provided in the following languages:
• English
• Arabic
• Brazilian Portuguese
• French
• German
• Hebrew
• Japanese
• Korean
• Spanish
• Traditional Chinese
DANGER
4L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
DANGER
6L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
PERIGO
PERIGO
PERIGO
PERIGO
8L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
DANGER
DANGER
DANGER
DANGER
DANGER
10 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
VORSICHT
VORSICHT
VORSICHT
VORSICHT
12 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
14 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
16 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
18 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
20 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Chapter 2. Important service information
This chapter introduces the following important service information that applies to all machine types
supported by this manual:
• “Strategy for replacing FRUs” on page 21
– “Strategy for replacing a hard disk drive or a solid-state drive” on page 21
– “Important notice for replacing a system board” on page 22
– “How to use error codes” on page 22
• “Strategy for replacing FRUs for CTO, special-bid, and standard models” on page 22
– “Product definition” on page 22
– “FRU identification” on page 23
Important:
• Advise customers to contact the Lenovo® Customer Support Center if they need any assistance in
obtaining or installing any software fixes, drivers, and UEFI BIOS downloads. Telephone numbers for
Lenovo Support are available at:
https://pcsupport.lenovo.com/supportphonelist
• System disassembly and reassembly videos that show the FRU removal or replacement procedures for
the Lenovo authorized service technicians are available at:
http://www.lenovoservicetraining.com/ion/
Strategy for replacing FRUs
Before replacing parts:
Ensure that all software fixes, drivers, and UEFI BIOS downloads are installed before you replace any FRUs
listed in this manual.
After a system board is replaced, ensure that the latest UEFI BIOS is loaded to the system board before you
complete the service action.
To download and install software fixes, drivers, and UEFI BIOS, go to https://support.lenovo.com and follow
the instructions on the screen.
Use the following strategy to prevent unnecessary expense for replacing and servicing FRUs:
• If you are instructed to replace a FRU but the replacement does not correct the problem, reinstall the
original FRU before you continue.
• Some computers have both a processor board and a system board. If you are instructed to replace either
the processor board or the system board, and replacing one of them does not correct the problem,
reinstall that board, and then replace the other one.
• If an adapter or a device consists of more than one FRU, any of the FRUs might be the cause of the error.
Before replacing the adapter or device, remove the FRUs, one by one, to see if the symptoms change.
Replace only the FRU that changed the symptoms.
Strategy for replacing a hard disk drive or a solid-state drive
Always try to run a low-level format operation before replacing a hard disk drive or a solid-state drive. This
will cause all customer data on the drive to be lost. Ensure that the customer has a current backup of the
data before you perform this task.
© Copyright Lenovo 2018 21
Attention: The drive startup sequence in the computer you are servicing might have been changed. Be
extremely careful during write operations such as copying, saving, or formatting. If you select an incorrect
drive, data or programs can be overwritten.
Important notice for replacing a system board
Some components mounted on a system board are very sensitive. Improper handling of a system board can
cause damage to those components, and may cause a system malfunction.
Attention: When handling a system board:
• Do not drop a system board or apply any excessive force to it.
• Avoid rough handling of any kind.
• Avoid bending a system board and hard pushing to prevent cracking at each Ball Grid Array (BGA)
chipset.
How to use error codes
Use the error codes displayed on the screen to diagnose failures. If more than one error code is displayed,
begin the diagnosis with the first error code. Whatever causes the first error code might also cause false error
codes. If no error code is displayed, see whether the error symptom is listed in the “Symptom-to-FRU Index”
section.
Strategy for replacing FRUs for CTO, special-bid, and standard models
This topic provides information about the model types and FRU identification.
Product definition
This topic introduces different model types and how to identify each type.
Dynamic Configure To Order (CTO) model
This model provides the ability for a customer to configure a Lenovo solution from a Web site, and have this
configuration sent to fulfillment, where it is built and shipped directly to the customer. The machine label and
eSupport will load these products as the 4-character MT, 4-character model, and 2-character country code.
The model is “CTO1” and the default country code is “WW” (example: 20AACTO1WW).
Special-bid model
This model is a unique configuration that has been negotiated between Lenovo and the customer. A unique
MTM consists of a 4-character MT, a 4-character model, and a numeric 2-character country code is provided
to the customer to place orders (example: 20AA000955). The country code assigned is numeric and does not
designate a specific country or region. The custom model factsheet for the MTM indicates which country the
special-bid MTM is set up for. Special-bid offering is not generally announced.
Standard model
Standard models (fixed configuration) are announced and offered to all customers. The MTM portion of the
machine label consists of a 4-character MT, a 4-character model, and an alphabetic 2-character country
code. The country code assigned is alphabetic and represents a designated country or region (example:
20AA0009UK).
22 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
FRU identification
Use Lenovo eSupport to identify major FRUs, FRU part numbers, and FRU descriptions for a product at an
MT - serial number level. Examples of major FRUs are hard disk drive, system board, and liquid crystal
display (LCD).
To identify the major FRUs for a product, do the following:
1. Go to:
https://support.lenovo.com/ibasepartslookup
2. Type the Machine Type in the corresponding field to get a general FRU list. Or type the Serial Number for
more detailed FRU information.
Chapter 2.Important service information 23
24 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Chapter 3. General checkout
This chapter presents following information:
• “What to do first” on page 25
• “Checkout guide” on page 26
• “Power system checkout” on page 28
Some descriptions in this chapter might not apply to your particular computer.
Before you go to the checkout guide, be sure to read the following important notes.
Important notes:
• Only certified trained personnel should service the computer.
• Before replacing any FRU, read the entire page on removing and replacing FRUs.
• When you replace FRUs, it is recommended to use new nylon-coated screws.
• Be extremely careful during such write operations as copying, saving, or formatting. Drives in the computer
that you are servicing sequence might have been altered. If you select an incorrect drive, data or programs might be
overwritten.
• Replace a FRU only with another FRU of the correct model. When you replace a FRU, ensure that the model of
the machine and the FRU part number are correct.
• A FRU should not be replaced because of a single, unreproducible failure. Single failures can occur for a variety
of reasons that have nothing to do with a hardware defect, such as cosmic radiation, ESD, or software errors.
Consider replacing a FRU only when a problem recurs. If you suspect that a FRU is defective, clear the error log and
run the test again. If the error does not recur, do not replace the FRU.
• Be careful not to replace a nondefective FRU.
What to do first
When you return a FRU, you must include the following information in the parts exchange form or parts return
form that you attach to it:
1. Name and phone number of service technician
2. Date of service
3. Date on which the machine failed
4. Date of purchase
5. Failure symptoms, error codes appearing on the display, and beep symptoms
6. Procedure index and page number in which the failing FRU was detected
7. Failing FRU name and part number
8. Machine type, model number, and serial number
9. Customer's name and address
Note: During the warranty period, the customer may be responsible for repair costs if the computer damage
was caused by misuse, accident, modification, unsuitable physical or operating environment, or improper
maintenance by the customer. Following is a list of some common items that are not covered under warranty
and some symptoms that might indicate that the system was subject to stress beyond normal use.
Before checking problems with the computer, determine whether the damage is covered under the warranty
by referring to the following list:
The following are not covered under warranty:
• LCD panel cracked from the application of excessive force or from being dropped
• Scratched (cosmetic) parts
© Copyright Lenovo 2018 25
• Distortion, deformation, or discoloration of the cosmetic parts
• Plastic parts, latches, pins, or connectors that have been cracked or broken by excessive force
• Damage caused by liquid spilled into the system
• Damage caused by the improper insertion of a PC Card or the installation of an incompatible card
• Improper disc insertion or use of an optical drive
• Diskette drive damage caused by pressure on the diskette drive cover, foreign material in the drive, or the
insertion of a diskette with multiple labels
• Damaged or bent diskette eject button
• Fuses blown by attachment of a nonsupported device
• Forgotten computer password (making the computer unusable)
• Sticky keys caused by spilling a liquid onto the keyboard
• Use of an incorrect ac power adapter on laptop products
The following symptoms might indicate damage caused by nonwarranted activities:
• Missing parts might be a symptom of unauthorized service or modification.
• Check for obvious damage to a hard disk drive. If the spindle of a hard disk drive becomes noisy, the hard
disk drive might have been dropped or subject to excessive force.
Checkout guide
Use the following procedures as a guide in identifying and correcting problems with the ThinkPad notebook
computer.
Note: The diagnostic tests are intended to test only ThinkPad products. The use of non-ThinkPad products,
prototype cards, or modified options can lead to false indications of errors and invalid system responses.
1. Identify the failing symptoms in as much detail as possible.
2. Verify the symptoms. Try to re-create the failure by running the diagnostic test or by repeating the
operation.
Diagnosing problems
Many computer problems can be solved without outside assistance. If you experience a problem with your
computer, the first place to start is the troubleshooting information in your computer documentation. If you
suspect a software problem, see the documentation, including readme files and help information systems,
that come with the operating system or program.
Lenovo Vantage is preinstalled on your computer. It supports the hardware scan function. It combines
diagnostic tests, system information collection, security status, and support information, along with hints and
tips for optimal system performance.
Note: If you are unable to isolate and repair the problem yourself after running the program, save and print
the log files created by the program. You need the log files when you speak to a Lenovo technical support
representative.
The troubleshooting information or the diagnostic programs might tell you that you need additional or
updated device drivers or other software. You can get the latest technical information and download device
drivers and updates from the Lenovo Support Web site at:
https://support.lenovo.com
For additional information, see the help system of the program.
26 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Quick test programs
Run quick test programs to troubleshoot and resolve computer problems, especially when the computer
does not have the Lenovo Solution center installed.
To download and install a quick test program, go to https://www.lenovo.com/diags, and follow the instructions
on the Web site.
To run a test using quick test program, do the following:
1. Go to the C:\SWTOOLS\ldiag directory.
2. Double-click the lsc_lite.exe file.
3. When the User Account Control window opens, click Yes.
4. Select the device class to be tested.
5. Select the devices to be tested.
6. Select the test to be performed.
7. Follow the instructions on the screen to start the test. When a problem is detected, information
messages are displayed. Refer to the messages to troubleshoot the problem.
UEFI diagnostic program
A UEFI diagnostic program is preinstalled on the computer. This program enables you to view system
information and test some hardware devices in your computer, such as memory, storage devices, the LCD,
and system board buses.
To run the UEFI diagnostic program, do the following:
1. Turn on the computer. If the computer cannot be turned on, go to “Power system checkout” on page 28,
and check the power sources. If an error code is displayed, go to “Symptom-to-FRU index” on page 35
for error code descriptions and troubleshooting hints.
2. When the ThinkPad logo is displayed, repeatedly press and release the F10 key. The main screen of the
UEFI diagnostic program is displayed.
3. Follow the instructions on the screen to use the program.
The following table displays the main items of the UEFI diagnostic program. Depending on the model, the
items might differ slightly.
Table 1. Items on the main screen of the UEFI diagnostic program
Tests Tools
• Memory quick test
• Memory extended test
• Memory bit fade test (180 min)
• Quick storage device test
• LCD test
• PCI-e test
• Motherboard buses test
• Exit application
• System information
• Generate configuration file
• Execute from configuration file
• Recover bad sectors tool
Note: The recover bad sectors tool is only available on computers that have hard disk drives installed.
Chapter 3.General checkout 27
Bootable diagnostic programs
If the computer you are servicing is not installed with the UEFI diagnostic program, you can download a
bootable diagnostic program from the Lenovo Support Web site. The bootable diagnostic program enables
you to view system information and test some hardware devices in your computer, such as memory, storage
devices, the LCD, and system board buses. To use the bootable diagnostic program, you can create a
bootable diagnostic medium using a USB device or disc.
To create a bootable diagnostic medium, do the following:
1. Go to https://www.lenovo.com/diags.
2. Click Lenovo Bootable Diagnostics.
3. Follow the instructions on the Web site to create a bootable diagnostic medium on a USB device or disc.
To use the diagnostic medium you have created, do one of the following:
• If you have created the bootable diagnostic medium on a USB device, do the following:
1. Attach the USB device to the computer.
2. Turn on the computer. If the computer cannot be turned on, go to “Power system checkout” on page
28, and check the power sources. If an error code is displayed, go to “Symptom-to-FRU index” on
page 35 for error code descriptions and troubleshooting hints.
3. When the ThinkPad logo is displayed, repeatedly press and release the F12 key. When the Boot Menu
window opens, release the F12 key.
4. Use the arrow keys to select USB HDD and then press Enter. The diagnostic program launches.
5. Follow the instructions on the screen to use the diagnostic program.
• If you have created the bootable diagnostic medium using a disc, do the following:
1. Turn on the computer. If the computer cannot be turned on, go to “Power system checkout” on page
28, and check the power sources. If an error code is displayed, go to “Symptom-to-FRU index” on
page 35 for error code descriptions and troubleshooting hints.
2. Insert the disc into the optical drive.
3. Restart the computer.
4. When the ThinkPad logo is displayed, repeatedly press and release the F12 key. When the Boot Menu
window opens, release the F12 key.
5. Use the arrow keys to select ATAPI CDx (x: 0, 1, ...) and then press Enter. The diagnostic program
launches.
6. Follow the instructions on the screen to use the diagnostic program.
Power system checkout
To verify if a battery pack or an ac power adapter is functional, do the following:
1. Turn off the computer.
2. Connect the ac power adapter.
3. Turn on the computer. If the computer can be turned on, it means that either the battery or the ac power
adapter is functional.
4. Insert a straightened paper clip into the emergency-reset hole to reset the computer. If the computer is
still powered on, it means that the ac power adapter is functional.
5. Turn off the computer.
6. Disconnect the ac power adapter and turn on the computer. If the computer can be turned on, it means
that the battery is functional.
If you suspect a power problem, see the appropriate one of the following power supply checkouts:
• “Checking the ac power adapter” on page 29
28 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
• “Checking operational charging” on page 29
• “Checking the battery pack” on page 29
• “Checking the coin-cell battery” on page 30
Checking the ac power adapter
You are here because the computer fails only when the ac power adapter is used.
• If the power problem occurs only when the docking station or the port replicator is used, replace the
docking station or the port replicator.
• If the system status indicator does not blink three times when an ac power source is connected, check the
power cord of the ac power adapter for correct continuity and installation.
• If the computer does not charge during operation, go to “Checking operational charging” on page 29.
Note: Noise from the ac power adapter does not always indicate a defect.
Checking the USB-C type ac power adapter
To check the USB-C type ac power adapter, do the following:
1. Connect the computer to a power outlet and turn on the computer.
2. Start Lenovo Vantage program, and then click Hardware Settings ➙ Power. The ac power adapter
information is displayed.
Ensure that you use the USB-C type ac power adapter that is shipped with the computer to provide enough
power to the computer. Otherwise, a message will be displayed, prompting you that the computer will not be
charged or will be charged slowly.
Checking operational charging
To check whether the battery pack charges correctly during operation, do the following:
1. Discharge the battery pack until the remaining battery power is less than 50%.
2. Connect the computer to ac power to charge the battery pack. If the battery status icon in the Windows
notification area indicates that the batteries are not charging, remove the battery pack and let them
return to room temperature.
3. Reinstall the battery pack. If the batteries are still not charging, replace the battery pack.
4. Check the battery status icon again. If the same error still exists, replace the system board. Otherwise,
check the original battery pack. See “Checking the battery pack” on page 29.
Checking the battery pack
This system supports only batteries specially designed for this specific system and manufactured by Lenovo
or an authorized builder. The system does not support unauthorized batteries or batteries designed for other
systems. If an unauthorized battery pack or a battery pack designed for another systems is installed, the
system will not charge.
Attention: Lenovo has no responsibility for the performance or safety of unauthorized batteries, and
provides no warranties for failures or damage arising out of their use.
The battery status icon in the Windows notification area displays the percentage of battery power remaining.
Move your pointer to the battery-status icon in the Windows notification area to check the battery status. The
battery-status icon displays the percentage of battery power remaining and how long you can use your
computer before you must charge the battery.
Note: If the battery pack becomes hot, it may not be able to charge. Remove it from the computer and leave
it at room temperature for a while. After it cools down, reinstall and recharge it.
Chapter 3.General checkout 29
To check the battery pack, do the following:
1. Power off the computer.
2. Remove the battery pack and measure the voltage between battery terminals 1 (+) and 7 (-). See the
following figure:
1(+)2(+) 3456(-)7(-)
Terminal Voltage (V dc)
1, 2 + 0 to + 12.6
6, 7 Ground (-)
3. If the voltage is less than +11.0 V dc, the battery pack has been discharged.
If the voltage is still less than +11.0 V dc after recharging, replace the battery pack.
4. If the voltage is more than +11.0 V dc, measure the resistance between battery terminals 5 and 7. The
resistance must be 4 to 30 K Ω. If the resistance is not correct, replace the battery pack. If the resistance
is correct, replace the system board.
Checking the coin-cell battery
Do the following:
1. Power off the computer, and unplug the ac power adapter from it.
2. Turn the computer upside down.
3. Remove the battery pack (see “1090 Battery” on page 75).
4. Remove the coin-cell battery (see “1070 Coin-cell battery” on page 73).
5. Measure the voltage of the battery. See the following figure.
Wire Voltage (V dc)
Red +2.5 to +3.2
Black Ground
• If the voltage is correct, replace the system board.
• If the voltage is not correct, replace the coin-cell battery.
• If the coin-cell battery discharges quickly after replacement, replace the system board.
30 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Chapter 4. Related service information
This chapter presents following information:
• “Recovery overview for the Windows 10 operating system” on page 31
• “Passwords” on page 32
• “Power management” on page 34
• “Symptom-to-FRU index” on page 35
Service Web site:
When the latest maintenance diskette and the system program service diskette become available, they will
be posted on:
https://support.lenovo.com
Recovery overview for the Windows 10 operating system
The Windows recovery programs enable you to reset your computer or use advanced startup options.
It is recommended that you create a recovery USB drive as early as possible. Store the recovery USB drive
as a backup or replacement for the Windows recovery programs.
For more information, see “Creating and using a recovery USB drive” on page 32.
Resetting your computer
If your computer does not perform well, you might consider resetting your computer. In the resetting
process, you can choose to keep your files or remove them, and then reinstall the Windows operating
system.
To reset your computer, do the following:
Note: The graphical user interface (GUI) items of the operating system might change without notice.
1. Open the Start menu and then click Settings ➙ Update & Security ➙ Recovery.
2. In the Reset this PC section, click Get started.
3. Follow the instructions on the screen to reset your computer.
Using advanced startup options
With advanced startup options, you can change the firmware settings of the computer, change the startup
settings of the Windows operating system, start the computer from an external device, or restore the
Windows operating system from a system image.
To use advanced startup options, do the following:
Note: The GUI items of the operating system might change without notice.
1. Open the Start menu and then click Settings ➙ Update & Security ➙ Recovery.
2. In the Advanced startup section, click Restart now ➙ Troubleshoot ➙ Advanced options.
3. Select a desired startup option, then follow the instructions on the screen.
© Copyright Lenovo 2018 31
Recovering your operating system if Windows 10 fails to start
The Windows recovery environment on your computer is capable of operating independently from the
Windows 10 operating system. This enables you to recover or repair the operating system even if the
Windows 10 operating system fails to start.
After two consecutive failed boot attempts, the Windows recovery environment starts automatically. Then
you can choose repair and recovery options by following the instructions on the screen.
Note: Ensure that your computer is connected to ac power during the recovery process.
Creating and using a recovery USB drive
You can create a recovery USB drive as a backup for the Windows recovery programs. With the recovery
USB drive, you can troubleshoot and fix the problems even if the preinstalled Windows recovery programs
are damaged.
Creating a recovery USB drive
The USB drive that you use to create the recovery USB drive must be at least 16 GB of storage. The actual
USB capacity that is required depends on the size of the recovery image.
Attention: The creation process deletes anything stored on the USB drive. To avoid data loss, make a
backup copy of all the data that you want to keep.
To create a recovery USB drive, do the following:
Note: Ensure that your computer is connected to ac power during the following process.
1. Connect a proper USB drive (at least 16 GB of storage).
2. Type recovery in the search box on the taskbar. Then click Create a recovery drive.
3. Click Yes in the User Account Control window to allow the Recovery Media Creator program to start.
4. In the Recovery Drive window, follow the on-screen instructions to create a recovery USB drive.
Using the recovery USB drive
If you cannot start your computer, use the recovery USB drive to recover your computer.
To use a recovery USB drive, do the following:
Note: Ensure that your computer is connected to ac power.
1. Connect the recovery USB drive to the computer.
2. Turn on or restart the computer. Before the Windows operating system starts, repeatedly press the F12
key. The Boot Menu window opens.
3. Select the recovery USB drive as the boot device.
4. Select a preferred keyboard layout.
5. Click Troubleshoot to display the optional recovery solutions.
6. Select a corresponding recovery solution according to your situation. Then follow the instructions on the
screen to complete the process.
Passwords
As many as three passwords might be needed for a ThinkPad notebook computer: the power-on password,
the hard disk password, and the supervisor password.
32 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
If any of these passwords has been set, a prompt for it will be displayed on the screen whenever the
computer is turned on. The computer does not start until the password is entered.
Note: If only a supervisor password is set, the password prompt will not be displayed when the operating
system is started.
Power-on password
A power-on password protects the system from being turned on by an unauthorized person. The password
must be entered before the operating system can be started. For instructions on how to remove the power-
on password, see “How to remove the power-on password” on page 33.
Hard disk password
There are two hard disk passwords:
• User hard disk password - for the user
• Master hard disk password - for the system administrator, who can use it to get access to the hard disk
even if the user has changed the user hard disk password.
Note: There are two modes for the hard disk password: User only and Master + User. The Master + User
mode requires two hard disk passwords; the system administrator enters both in the same operation. The
system administrator then provides the user hard disk password to the system user.
Attention: If the user hard disk password has been forgotten, check whether a master hard disk password
has been set. If a master hard disk password has been set, it can be used to access the hard disk drive. If no
master hard disk password is available, neither Lenovo nor Lenovo authorized service technicians provide
any services to reset either the user hard disk password or the master hard disk password, or to recover data
from the hard disk drive. The hard disk drive can be replaced for a scheduled fee.
For instructions on how to remove the hard disk password, see “How to remove the hard disk password” on
page 34.
Supervisor password
The supervisor password protects the system information stored in the ThinkPad Setup program. It provides
the following security features:
• If only a supervisor password is set, a password prompt is displayed when you try to start the ThinkPad
Setup program. Unauthorized users cannot change most of the system configuration options in the
ThinkPad Setup program without the password.
• The system administrator can use the supervisor password to access a computer even if the user of that
computer has set a power-on password. The supervisor password overrides the power-on password.
• The system administrator can set the same supervisor password on many ThinkPad notebook computers
to make administration easier.
Attention: If the supervisor password has been forgotten and cannot be made available to the service
technician, there is no service procedure to reset the password. The system board must be replaced for a
scheduled fee.
How to remove the power-on password
To remove the power-on password, do one of the following:
If no supervisor password has been set, do the following to remove the power-on password:
1. Turn off the computer.
Chapter 4.Related service information 33
2. Remove the battery pack. For instructions on how to remove the battery pack, see “1090 Battery” on
page 75.
3. Remove the coin-cell battery. For instructions on how to remove the coin-cell battery, see “1070 Coin-
cell battery” on page 73.
4. Turn on the computer and wait until the POST ends. After the POST ends, the password prompt will not
be displayed. The power-on password has been removed.
5. Reinstall the coin-cell battery and the battery pack.
If a supervisor password has been set and is known to the service technician, do the following to remove the
power-on password:
1. Turn on the computer.
2. When the ThinkPad logo is displayed, immediately press F1.
3. Type the supervisor password to enter the ThinkPad Setup program.
4. Select Security.
5. Select Password.
6. Select Power-On Password.
7. Type the current supervisor password in the Enter Current Password field. Then, leave the Enter New
Password field blank, and press Enter twice.
8. In the Changes have been saved window, press Enter.
9. Press F10 to save changes and exit the ThinkPad Setup program.
How to remove the hard disk password
Attention: If User only mode is selected and the user hard disk password has been forgotten and cannot be
made available to the service technician, neither Lenovo nor Lenovo authorized service technicians provide
any services to reset the user hard disk password, or to recover data from the hard disk drive. The hard disk
drive can be replaced for a scheduled fee. To put the system back to operational status, the only Lenovo and
Lenovo-authorized service solution would be to replace the hard disk drive or solid-state drive with a
scheduled fee.
To remove a user hard disk password that has been forgotten, when the supervisor password and the
master hard disk password are known, do the following:
1. Turn on the computer.
2. When the ThinkPad logo is displayed, immediately press F1 to enter the ThinkPad Setup program.
3. Select Security.
4. Select Password.
5. Select Hard-disk x password where x is the letter of the hard disk drive. A pop-up window opens.
6. Select Master HDP, where HDP stands for hard disk password.
7. Type the current master hard disk password in the Enter Current Password field. Then, leave the Enter
New Password field blank, and press Enter twice.
8. Press F10 to save changes and exit the ThinkPad Setup program. The user hard disk password and the
master hard disk password have been removed.
Power management
To reduce power consumption, the computer has two power management modes: sleep and hibernation.
Sleep mode
When the computer enters sleep mode, the following events occur:
34 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
• The LCD is powered off.
• The hard disk drive or solid-state drive is powered off.
• The microprocessor stops.
To put your computer into sleep mode, do the following:
• Open the Start menu, click Power, and then click Sleep.
In certain circumstances, the computer goes into sleep mode automatically:
• After a period of inactivity specified in power plan settings
• When the battery power is low
To cause the computer to return from sleep mode and resume operation, do one of the following:
• Press any key.
• Open the LCD cover.
• Turn on the power button.
Also, in either of the following events, the computer automatically returns from sleep mode and resumes
operation:
• The ring indicator (RI) is signaled by a serial device or a PC Card device.
• The time set on the resume timer elapses.
Note: The computer does not accept any input immediately after it enters sleep mode. Wait a few
seconds before taking any action to reenter operation mode.
Hibernation mode
In hibernation mode, the following occurs:
• The system status, RAM, VRAM, and setup data are stored on the hard disk drive or solid-state drive.
• The system is powered off.
Note: If the computer enters the hibernation mode while it is connected to the dock, do not disconnect it
before resuming normal operation. If you do disconnect it and then try to resume normal operation, you will
get an error message, and you will have to restart the system.
If you have defined one of the following actions as the event that causes the system to go into hibernation
mode, perform that action.
• Closing the lid.
• Pressing the power button.
Also, the computer goes into hibernation mode automatically after a period of inactivity specified in power
plan settings
When the power is turned on, the computer returns from hibernation mode and resumes operation. The
hibernation file in the boot record on the hard disk drive or solid-state drive is read, and system status is
restored from the hard disk drive or solid-state drive.
Symptom-to-FRU index
This section contains following information:
• “Numeric error codes” on page 36
• “Error messages” on page 38
• “No-beep symptoms” on page 39
Chapter 4.Related service information 35
• “LCD-related symptoms” on page 40
• “Intermittent problems” on page 40
• “Undetermined problems” on page 41
The symptom-to-FRU index in this section lists symptoms and errors and their possible causes. The most
likely cause is listed first, in boldface type.
Note: Do the FRU replacement or other actions in the sequence shown in the column headed “FRU or
action, in sequence.” If replacing a FRU does not solve the problem, put the original part back in the
computer. Do not replace a nondefective FRU.
This index can also help you determine, during regular servicing, what FRUs are likely to need to be replaced
next.
A numeric error is displayed for each error detected in POST or system operation. In the displays, n can be
any number.
If no numeric code is displayed, check the narrative descriptions of symptoms. If the symptom is not
described there, go to “Intermittent problems” on page 40.
Note: For a device not supported by diagnostic codes in the ThinkPad notebooks, see the manual for that
device.
Numeric error codes
Table 2. Numeric error codes
Symptom or error (beeps, if any) FRU or action, in sequence
0177
Bad SVP data, stop POST task—The checksum of the
supervisor password in the EEPROM is not correct.
Replace the system board.
0183
Bad CRC of Security Settings in EFI Variable. Enter the
ThinkPad Setup program. – The checksum of the Security
settings in the EFI Variable is not correct.
1. Run the ThinkPad Setup program. The settings
will be corrected automatically. Then save the
current settings by pressing F10.
2. Replace the system board.
0187
EAIA data access error - The access to EEPROM is failed.
Replace the system board.
0188
Invalid RFID Serialization Information Area.
Replace the system board.
0189
Invalid RFID configuration information area - The
EEPROM checksum is not correct.
Replace the system board.
0190
Critical low-battery error
1. Charge the battery pack.
2. Replace the battery pack.
0191
System Security - Invalid Remote Change requested.
1. Run the ThinkPad Setup program, and then save
current setting by pressing F10.
2. Replace the system board.
0199
System Security - Security password retry count
exceeded.
1. Run the ThinkPad Setup program. The retry count
will be reset. Then save the current settings by
pressing F10.
2. Replace the system board.
36 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Table 2. Numeric error codes (continued)
Symptom or error (beeps, if any) FRU or action, in sequence
0251
System CMOS checksum bad - Default configuration
used.
1. Charge the coin-cell battery for more than 8 hours
by connecting the ac power adapter.
2. Replace the coin-cell battery and run the ThinkPad
Setup program to reset the time and date.
0253
EFI Variable Block Data was destroyed.
1. Run ThinkPad Setup to reconfigure the settings.
2. Replace the system board.
0271
Real-Time Clock Error. Check Date and Time settings.
1. Run ThinkPad Setup to reset the time and date
2. Replace the coin-cell battery and run the ThinkPad
Setup program to reset the time and date.
1802
Unauthorized network card is plugged in - Turn off and
remove the network card.
1. Remove the network card.
2. Replace the system board.
1820
More than one external fingerprint reader is attached.
Power off and remove all but the reader that you set up
within your main operating system.
Remove all but the reader that you set up for the
authentication
2000
ThinkVantage Active Protection sensor diagnostics failed.
Have the computer serviced.
2100
Detection error on HDD0 (Main HDD) 1. Reseat the hard disk drive.
2. Replace the main hard disk drive.
3. Replace the system board.
2101
Detection error on HDD1 (Ultrabay HDD) 1. Reseat the hard disk drive.
2. Replace the Ultrabay® hard disk drive.
3. Replace the system board.
2102
Detection error on HDD2 (Mini SATA) 1. Reseat the Mini SATA device.
2. Replace the mini SATA device.
3. Replace the system board.
2110
Read error on HDD0 (Main HDD) 1. Reseat the hard disk drive.
2. Replace the main hard disk drive.
3. Replace the system board.
2111
Read error on HDD1 (Ultrabay HDD) 1. Reseat the hard disk drive.
2. Replace the Ultrabay hard disk drive.
3. Replace the system board.
2112
Read error on HDD2 (Mini SATA) 1. Reseat the Mini SATA device.
2. Replace the mini SATA device.
3. Replace the system board.
2200
Machine Type and Serial Number are invalid.
Replace the system board.
2201
Machine UUID is invalid
Replace the system board.
Chapter 4.Related service information 37
Error messages
Table 3. Error messages
Symptom or error (beeps, if any) FRU or action, in sequence
Fan error.
(four short beeps, one long beep)
1. Replace the fan.
2. Apply thermal grease.
3. Replace the system board.
Thermal sensing error. Replace the system board.
The battery installed is not supported by this system and
will not charge.
Please replace the battery with the correct Lenovo battery
for this system.
Press the ESC key to continue.
Replace the battery.
This system does not support batteries that are not
genuine Lenovo-made or authorized. The system will
continue to boot, but may not charge unauthorized
batteries.
Attention: Lenovo has no responsibility for the
performance or safety of unauthorized batteries, and
provides no warranties for failures or damage arising out
of their use.
Replace the battery.
Beep errors
Lenovo SmartBeep technology enables you to decode beep errors with your smartphone when a black
screen occurs with beeps from your computer. To decode the beep error with Lenovo SmartBeep
technology, do the following:
1. Go to https://support.lenovo.com/smartbeep or scan the following QR Code.
2. Download the proper diagnostic app and install it on your smartphone.
3. Run the diagnostic app and place the smartphone near the computer.
4. Press the Fn key on your computer to emit the beep again. The diagnostic app decodes the beep error
and shows possible solutions on the smartphone.
The following section describes some beep errors and the corresponding solutions.
Note: Do not attempt to service a product yourself unless instructed to do so by the Customer Support
Center or product documentation. Only use a Lenovo-authorized service provider to repair your product.
38 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Error codes Solutions
0001: Reset error (platform reset not de-asserted) 1. Remove the ac power adapter and the removable
battery if your computer has one. Then, reset the
computer by doing one of the following:
• For models with the the emergency-reset hole,
insert a straightened paper clip into the
emergency-reset hole. Wait for one minute.
Then, reconnect all power resources and restart
the computer.
• For models without the emergency-reset hole,
press and hold the power button for about
seven seconds. Then, reconnect to all power
resources and restart the computer.
2. Replace the system board (service provider only).
0002: Internal bus error Replace the system board (service provider only).
0281: General embedded controller error Replace the system board (service provider only).
0282: Memory module error 1. Reinstall or replace the memory module.
2. Replace the system board (service provider only).
0283: PCI resource error 1. Remove PCIe devices (the M.2 card, PCIe card,
and so on) (service provider only).
2. Replace the system board (service provider only).
0284: TCG-compliant functionality-related error (might be
the BIOS code validation failure) Replace the system board (service provider only).
0285: TCG-compliant functionality-related error (might be
the TPM initialization failure) Replace the system board (service provider only).
0286: Integrated graphics error Replace the system board (service provider only).
0287: Discrete graphics error 1. Reinstall or replace the discrete graphics card
(service provider only).
2. Replace the system board (service provider only).
0288: Computer display error 1. Reconnect the display cable on both the system
board side and the computer display side (service
provider only).
2. Replace the system board (service provider only).
No-beep symptoms
Table 4. No-beep symptoms
Symptom or error FRU or action, in sequence
No beep, power-on indicator on, LCD blank, and no
POST.
1. Ensure that every connector is connected tightly
and correctly.
2. Reseat memory module.
3. Replace the system board.
No beep, power-on indicator on, and LCD blank during
POST. 1. Reseat memory module..
2. Replace the system board.
Chapter 4.Related service information 39
Table 4. No-beep symptoms (continued)
Symptom or error FRU or action, in sequence
The power-on password prompt appears. A power-on password or a supervisor password is set.
Type the password and press Enter.
The hard-disk password prompt appears. A hard-disk password is set. Type the password and
press Enter.
LCD-related symptoms
Important: The TFT LCD for the notebook computer contains many thin-film transistors (TFTs). The
presence of a small number of dots that are missing, discolored, or always lighted is characteristic of TFT
LCD technology, but excessive pixel problems can cause viewing concerns.
If the LCD you are servicing has two or less visible defective pixels, it should not be considered faulty.
However, if the LCD has three or more visible defective pixels, it will be deemed as defective by Lenovo and
it should be replaced.
Notes:
• This policy applies to all ThinkPad Notebooks purchased on 1 January, 2008 or later.
• Lenovo will not provide warranty replacement if the LCD is within specifications because we cannot
guarantee that any replacement LCD will have zero pixel defects.
• One pixel consists of R, G, B sub-pixels.
Table 5. LCD-related symptoms
Symptom or error FRU or action, in sequence
No beep, power-on indicator on, and a blank LCD during
POST.
Replace the system board.
• LCD backlight not working.
• LCD too dark.
• LCD brightness cannot be adjusted.
• LCD contrast cannot be adjusted.
1. Reseat the LCD connectors.
2. Replace the LCD assembly.
3. Replace the system board.
• LCD screen unreadable.
• Characters missing pixels.
• Screen abnormal.
• Wrong color displayed.
1. See important note for “LCD-related symptoms.”
2. Reseat all LCD connectors.
3. Replace the LCD assembly.
4. Replace the system board.
Horizontal or vertical lines displayed on LCD. Replace the LCD assembly.
Intermittent problems
Intermittent system hang problems can be due to a variety of causes that have nothing to do with a hardware
defect, such as cosmic radiation, ESD, or software errors. FRU replacement should be considered only when
a problem recurs.
When analyzing an intermittent problem, do the following:
1. Run the diagnostic test for the system board in loop mode at least 10 times.
2. If no error is detected, do not replace any FRUs.
3. If any error is detected, replace the FRU shown by the FRU code. Rerun the test to verify that no more
errors exist.
40 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Undetermined problems
If the diagnostic tests did not identify the device that has failed, if wrong devices are installed, or if the
system simply is not operating, follow these procedures to isolate the failing FRU (do not isolate FRUs that
have no defects).
Verify that all attached devices are supported by the computer.
Verify that the power supply being used at the time of the failure is operating correctly. (See “Power system
checkout” on page 28)
1. Turn off the computer.
2. Visually check each FRU for damage. Replace any damaged FRU.
3. Remove or disconnect all of the following devices:
a. Non-ThinkPad devices
b. Devices attached to the dock
c. Printer, mouse, and other external devices
d. Battery pack
e. Hard disk drive or solid-state drive
f. External diskette drive or optical drive
g. Memory module
h. Optical disk or diskette in the internal drive
4. Turn on the computer.
5. Determine whether the problem has been solved.
6. If the problem does not recur, reconnect the removed devices one at a time until you find the failing FRU.
7. If the problem remains, replace the following FRUs one at a time (do not replace a nondefective FRU):
a. System board
b. LCD assembly
Chapter 4.Related service information 41
42 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Chapter 5. Special keys
The following table describes the functions of function keys and key combinations.
Table 6. Special keys
Special key Description
+Switch the function of the F1–F12 keys between the standard function and special function printed
as an icon on each key.
When the Fn Lock indicator is on:
• Press F1-F12 to use the standard function.
• Press Fn+F1-F12 to use the special function.
When the Fn Lock indicator is off:
• Press Fn+F1-F12 to use the standard function.
• Press F1-F12 to use the special function.
Mutes or unmutes the speakers.
When the key indicator is on, the speakers are muted.
If you mute the speakers and turn off your computer, the speakers remain muted when you turn on
your computer.
Decreases the speaker volume.
Increases the speaker volume.
Mutes or unmutes the microphones.
Darkens the display.
Brightens the display.
Manage external displays.
F8
Enables or disables the built-in wireless networking features.
F9
Open the Settings window.
F10
Enable or disable the built-in Bluetooth features.
F11
Open a keyboard setting page.
© Copyright Lenovo 2018 43
Table 6. Special keys (continued)
Special key Description
F12
Invoke the function defined by yourself. To define or change the action for the F12 key, do the
following:
1. Open the Start menu and click Lenovo Vantage.
2. Click Hardware Settings and then click input.
3. Locate the Keyboard: User-defined Key section and follow the on-screen instructions to
complete the setting.
On this setting page, you can also define different functions for the key combinations with F12, such
as Shift+F12, Alt+F12, or Ctrl+F12.
+Open the Snipping Tool program.
Fn+Spacebar If your computer supports keyboard backlight, press Fn+Spacebar to switch between the different
keyboard backlight status.
Fn+4 Puts your computer into sleep mode. To return to normal operation, press any key or the power
button.
Fn+B Has the same function as the Break key on a conventional keyboard.
Fn+K Has the same function as the ScrLK key on a conventional keyboard.
Fn+P Has the same function as the Pause key on a conventional keyboard.
Fn+S Has the same function as the SysRq key on a conventional keyboard.
Fn+Left arrow
key
This key combination has the same function as the Home key.
Fn+Right arrow
key
This key combination has the same function as the End key.
44 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Chapter 6. Locations
This chapter introduces the locations of the hardware components on your computer.
Locating computer controls, connectors, and indicators
This topic introduces the locations of the computer controls, connectors, and indicators.
Front
ThinkPad L390 Yoga™ and ThinkPad S2 Yoga 4th Gen
1 Infrared camera (available on some models) 2 Microphones
3 Front camera 4 Multi-touch screen
ThinkPad L390 and ThinkPad S2 4th Gen
© Copyright Lenovo 2018 45
1 Front camera 2 Microphones
3 Multi-touch screen (available on some models)
Base
1 Fingerprint reader* 2 Trackpad
3 NFC mark* 4 TrackPoint® pointing device
5 Rear camera*
* for selected models
Left-side view
1 Pen tether hole 2 USB-C™ connectors
3 Always On USB 3.1 connector Gen 1 4 HDMI™ connector
46 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Right-side view
1 Pen slot 2 Power button
3 Audio connector 4 microSD card slot
5 USB 3.1 connector Gen 1 6 Mini Ethernet connector
7 Security-lock slot 8 Pen tether hole
Bottom view
1 Emergency-reset hole 2 Speakers
Locating FRUs and CRUs
This topic introduces the following service parts:
• “Major FRUs and CRUs” on page 49
• “LCD FRUs and CRUs” on page 51
Chapter 6.Locations 47
Notes:
• Each FRU is available for all types or models, unless otherwise specified.
• CRU statement for customers:
You can resolve some problems with your product with a replacement part you can install yourself, called a
“Customer Replaceable Unit” or “CRU.” Some CRUs are designated as self-service CRUs and others are
designated as optional-service CRUs. Installation of self-service CRUs is your responsibility. For optional-service
CRUs, you can either install the CRU yourself or you can request that a Service Provider install the CRU according to
the warranty service for your product. If you intend on installing the CRU, Lenovo will ship the CRU to you. CRU
information and replacement instructions are shipped with your product and are available from Lenovo at any time
upon request. You can find a list of CRUs for your product in this Hardware Maintenance Manual. An electronic
version of this manual can be found at https://support.lenovo.com. Click Documentation and then follow the on-
screen instructions to find the manual for your product. You might be required to return the defective CRU. When
return is required: (1) return instructions, a prepaid shipping label, and a container will be included with the
replacement CRU; and (2) you might be charged for the replacement CRU if Lenovo does not receive the defective
CRU within thirty (30) days of your receipt of the replacement CRU. See your Lenovo Limited Warranty
documentation for full details.
ThinkPad computers contain the following types of CRUs and FRUs:
– Self-service CRUs: Refer to parts that can be installed or replaced easily by customer themselves or by trained
service technicians at an additional cost.
– Optional-service CRUs: Refer to parts that can be installed or replaced by customers with a greater skill level.
Trained service technicians can also provide service to install or replace the parts under the type of warranty
designated for the customer’s machine.
– FRU: Refer to parts that must be installed or replaced only by trained service technicians. If customers choose to
replace the FRUs by themselves, the product warranty might be affected.
48 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Note: Depending on the computer model, your computer might look different from the illustration above.
Table 7. Major FRUs and CRUs
No. FRU description Self-service CRU Optional-service CRU
1LCD unit No No
2Keyboard No Yes
3Keyboard bezel assembly No No
4Thermal fan No No
5System board No No
6USB 3.1 connector bracket No No
7Speaker assembly No No
8Wireless LAN antenna assembly No No
9Rear camera board* No No
10 Rear camera board cable* No No
11 NFC board cable* No No
12 NFC board* No No
13 NFC antenna* No No
14 Base cover assembly Yes No
15 Battery No No
16 ThinkPad Pen Pro charger with cable* No No
17 ThinkPad Pen Pro holder* No No
18 ThinkPad Pen Pro* No No
19 Power button board cable No No
20 Power button board No No
21 Fingerprint reader cable* No No
22 Fingerprint reader* No No
23 Fingerprint reader bracket* No No
24 Coin-cell battery No Yes
25 Long M.2 solid-state drive* No Yes
26 Short M.2 solid-state drive* No Yes
27 M.2 solid-state drive bracket* No Yes
28 HDMI connector bracket No No
29 Wireless LAN card No Yes
30 Memory module No Yes
31 Trackpad No No
32 Trackpad cable No No
33 TrackPoint cap Yes No
aLenovo factory recovery USB key 1No No
50 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Table 7. Major FRUs and CRUs (continued)
No. FRU description Self-service CRU Optional-service CRU
bMiscellaneous parts kits No No
cPower cord Yes No
dac power adapter Yes No
Notes:
• * for selected models.
• 1 The Lenovo factory recovery USB key is used to restore the Microsoft Windows operating system. It
might not come with the computer, and a user might order it from https://pcsupport.lenovo.com/
lenovorecovery, though additional shipping and handling fees might apply.
LCD FRUs and CRUs
For Yoga models
Chapter 6.Locations 51
Table 8. LCD FRUs and CRUs
No. FRU description Self-service CRU Optional-service CRU
1Rubber caps No No
2Strip cover No No
3Touch module assembly No No
4Infrared camera No No
5Sensor board No No
6Infrared camera/microphone module cable No No
7Sensor board cable No No
8ThinkPad-logo-LED card with cable No No
9RGB camera/microphone module No No
10 RGB camera/microphone module cable No No
11 LCD rear cover assembly No No
12 Hinge rubber No No
13 LCD hinges No No
14 LCD cable No No
15 Touch control board No No
52 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
For non-Yoga models
Table 9. LCD FRUs and CRUs
No. FRU description Self-service CRU Optional-service CRU
1LCD bezel No No
2LCD panel No No
3RGB camera/microphone module No No
4RGB camera/microphone module/ThinkPad-
logo-LED card cable
No No
5LCD rear cover assembly No No
6LCD hinges No No
7LCD cable No No
Chapter 6.Locations 53
Miscellaneous parts
Table 10. Miscellaneous part
FRU descriptions Self-service
CRU
Optional-service
CRU
Screw kit:
• Screw M2 x L4, black (15)
• Screw M2 x L2.5, black (10)
• Screw M2 x L2, black (2)
• Screw M2 x L2, silver (4)
• Screw M2.5 x L2.5, black (6)
• Screw M2 x L3, black (4)
• Screw M2.5 x L4.5, silver (6)
• Spec
No No
Keyboard removal tool No No
Connector and cable guide
This topic provides information to help Lenovo authorized service technicians identify connectors and cables
for replacement purpose. To view each FRU and the exploded illustration of the computer, see “Major FRUs
and CRUs” on page 49 and “LCD FRUs and CRUs” on page 51.
Note: Depending on your computer model, some connectors or cables might not be available.
System board connectors and cables
54 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Table 11. System board connector and cable guide
Item Connector (location) Internal cable required Cable connection
1Sensor board connector Sensor board connector cable Connect one end to the sensor
board and the other end to this
connector.
2Wireless-LAN card slot (internal) No Insert the wireless-LAN card into
this slot.
3Thermal fan connector (internal) Thermal fan assembly cable The thermal fan assembly comes
with cable. Connect the cable to
this connector.
4M.2 solid-state drive connector
(internal)
No Insert the M.2 solid-state drive into
this slot.
5Memory module slots (internal) No Insert the memory module into this
slot.
6Rear camera board connector
(internal)
Rear camera board cable Connect one end to the rear
camera board connector on the
rear camera board and the other
end to this connector.
7LCD connector (internal) LCD cable Connect one end to the LCD panel
and the other end to this
connector.
8 9 USB-C connectors (external) No Connect a USB-C compatible
device to this connector.
10 Always On USB 3.1 connector
Gen 1 (external)
No Connect USB 3.1-compatible
devices to this connector.
11 HDMI connector (external) No Connect a compatible digital audio
device or video monitor to this
connector.
12 NFC board connector (internal) NFC board cable Connect one end to this connector
and the other end to the NFC
board.
13 Battery connector (internal) No Connect the battery to this
connector.
14 Trackpad connector (internal) Trackpad cable Connect one end to the trackpad
and the other end to this
connector.
15 Coin-cell battery connector
(internal)
Coin-cell battery cable The coin-cell battery comes with
cable. Connect the cable to this
connector.
16 Fingerprint reader card connector
(internal)
Fingerprint reader cable Connect one end to the fingerprint
reader connector on the fingerprint
reader card and the other end to
this connector.
17 Speaker assembly connector
(internal)
Speaker assembly cable The speaker assembly comes with
cable. Connect the cable to this
connector.
18 Power button board connector Power button board cable Power button board comes with
cable. Connect the cable to this
connector.
Chapter 6.Locations 55
Table 11. System board connector and cable guide (continued)
Item Connector (location) Internal cable required Cable connection
19 Audio connector (external) No Connect headphones or a headset
with 3.5-mm (0.14-inch) 4-pole
plug to this connector.
20 USB 3.1 connector Gen 1 No Connect USB 3.1-compatible
devices to this connector.
21 Mini Ethernet connector No Connect your computer to a local
network through the mini Ethernet
connector on your computer with
an Ethernet cable. To attach an
Ethernet cable to your computer,
you need an Ethernet extension
adapter.
22 microSD card connector (internal) No Insert the microSD card into this
slot.
23 TrackPoint pointing stick
connector (internal)
TrackPoint pointing stick cable The TrackPoint pointing stick
comes with cable. Connect the
cable to this connector.
24 Keyboard connector (internal) Keyboard assembly cable The keyboard assembly comes
with cable. Connect the cable to
this connector.
Sensor board connector and cable
Table 12. Sensor board
Item Connector (location) Internal cable required Cable connection
1RGB camera connector (internal) RGB camera cable Connect one end to the RGB
camera and the other end to this
connector.
2Infrared camera connector
(internal)
Infrared camera cable Connect one end to the infrared
camera and the other end to this
connector.
3Sensor board connector (internal) Sensor board cable Connect one end to the system
board and the other end to this
connector.
4ThinkPad-logo-LED card
connector (internal)
No The ThinkPad-logo-LED card
comes with cable. Connect the
cable to this connector.
56 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Trackpad connector and cable
Table 13. Trackpad connector
Item Connector (location) Internal cable required Cable connection
1Trackpad connector (internal) Trackpad cable Connect one end to the trackpad
connector on the system board
and the other end to this
connector.
Power button board connector and cable
Table 14. Power button board connector
Item Connector (location) Internal cable required Cable connection
1ThinkPad Pen Pro charger
connector (internal)
No The ThinkPad Pen Pro charger
comes with cable. Connect the
cable to this connector.
2Power button board connector
(internal)
Power button board cable Connect one end to the power
button board connector on the
system board and the other end to
this connector.
RGB camera/microphone module connector and cable (for Yoga models only)
Table 15. RGB camera/microphone module connector
Item Connector (location) Internal cable required Cable connection
1RGB camera/microphone module
connector (internal)
RGB camera/microphone module
cable
Connect one end to the RGB
camera/microphone module
connector on the sensor board
and the other end to this
connector.
RGB camera/microphone module connector and cable (for non-Yoga models only)
Chapter 6.Locations 57
Table 16. RGB camera/microphone module connector
Item Connector (location) Internal cable required Cable connection
1RGB camera/microphone module
connector (internal)
RGB camera/microphone module
cable
Connect one end to the RGB
camera/microphone module
connector on the system board
and the other end to this
connector.
Rear camera board connector and cable (for Yoga models only)
Table 17. Rear camera board connector
Item Connector (location) Internal cable required Cable connection
1Rear camera board connector
(internal)
Rear camera board cable Connect one end to the rear
camera board connector on the
system board and the other end to
this connector.
Infrared camera board connector and cable (for Yoga models only)
Table 18. Infrared camera board connector
Item Connector (location) Internal cable required Cable connection
1Infrared camera board connector
(internal)
Infrared camera board cable Connect one end to the infrared
camera board connector on the
sensor board and the other end to
this connector.
Fingerprint reader card connector and cable
Table 19. Fingerprint reader card
Item Connector (location) Internal cable required Cable connection
1Fingerprint reader card connector
(internal)
Fingerprint reader cable Connect one end to the fingerprint
reader connector on the system
board and the other end to this
connector.
58 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
LCD panel connector (for non-Yoga models only)
Table 20. LCD panel
Item Connector (location) Internal cable required Cable connection
1LCD panel connector (internal) LCD cable Connect one end to the LCD
connector on the system board
and the other end to this
connector.
Touch module assembly connector (for Yoga models only)
Table 21. Touch module assembly
Item Connector (location) Internal cable required Cable connection
1Touch module assembly
connector
LCD cable Connect one end to the LCD
connector on the system board
and the other end to this
connector.
Chapter 6.Locations 59
Wireless-LAN card connectors and cables
Table 22. Wireless-LAN card
Item Connector (location) Internal cable required Cable connection
1Wireless-LAN antenna connector
(internal)
Wireless-LAN antenna kit Connect one end of the wireless-
LAN gray antenna to the C-cover
and the other end to this
connector.
2Wireless-LAN antenna connector
(internal)
Wireless-LAN antenna kit Connect one end of the wireless-
LAN black antenna to the C-cover
and the other end to this
connector.
NFC board connectors and cables
Table 23. NFC board
Item Connector (location) Internal cable required Cable connection
1NFC board connector (internal) NFC cable Connect one end of the NFC cable
to the system board and the other
end to this connector.
2NFC attenna connector (internal) NFC attenna The NFC attenna comes with
cable. Connect the cable to this
connector.
Looking up FRU information
For detailed FRU information, including part numbers, descriptions, and substitution part numbers, go to:
https://support.lenovo.com/partslookup
60 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Chapter 7. FRU replacement notices
This chapter presents notices related to removing and replacing parts. Read this chapter carefully before
replacing any FRU.
CRU statement for customers:
You can resolve some problems with your product with a replacement part you can install yourself, called a
“Customer Replaceable Unit” or “CRU.” Some CRUs are designated as self-service CRUs and others are
designated as optional-service CRUs. Installation of self-service CRUs is your responsibility. For optional-
service CRUs, you can either install the CRU yourself or you can request that a Service Provider install the
CRU according to the warranty service for your product. If you intend on installing the CRU, Lenovo will ship
the CRU to you. CRU information and replacement instructions are shipped with your product and are
available from Lenovo at any time upon request. You can find a list of CRUs for your product in this Hardware
Maintenance Manual. An electronic version of this manual can be found at https://support.lenovo.com. Click
Documentation and then follow the on-screen instructions to find the manual for your product. You might be
required to return the defective CRU. When return is required: (1) return instructions, a prepaid shipping label,
and a container will be included with the replacement CRU; and (2) you might be charged for the
replacement CRU if Lenovo does not receive the defective CRU within thirty (30) days of your receipt of the
replacement CRU. See your Lenovo Limited Warranty documentation for full details.
This chapter presents notices related to removing and replacing parts. Read this chapter carefully before
replacing any FRU.
Service tool kit
Ensure that the following common service tool kit is prepared before you service a ThinkPad notebook
computer.
No. Tool name Tool type
1 Phillips-head screwdriver Common tool
2 Torx-head screwdriver Common tool
3Conductive tweezers Common tool
5Hexagonal socket Consumable tool
6Silicone grease Consumable tool
7 Polyamide tape Consumable tool
8 Mylar tape Consumable tool
9 Eraser Consumable tool
10 Electrical tape Consumable tool
11 Double-sided tape Consumable tool
12 Conductive tape Consumable tool
Note: The silicone grease can be applied to the surfaces of the microprocessor and heatsink to eliminate air
gaps. The hexagonal socket is used to pick up the antenna connectors.
© Copyright Lenovo 2018 61
Screw notices
Loose screws can cause a reliability problem. In the ThinkPad notebook computer, this problem is
addressed with special nylon-coated screws that have the following characteristics:
• They maintain tight connections.
• They do not easily come loose, even with shock or vibration.
• They are harder to tighten.
Do the following when you service the computer:
• Keep the screw kit in your tool bag. For the part number of the screw kit, go to:
https://support.lenovo.com/partslookup
• It is recommended to use new screws.
• It is recommended to use each screw only once.
Tighten screws as follows:
• Plastic to plastic
Turn an additional angle of 90 degrees after the screw head touches the surface of the plastic part.
• Logic card to plastic
Turn an additional angle of 180 degrees after the screw head touches the surface of the logic card.
Notes:
• Ensure that you use the correct screw. It is recommended to use new screws for replacements. If you
have a torque screwdriver, tighten all screws firmly to the torque specified in the screw information table
for each step.
• Ensure torque screwdrivers are calibrated correctly following country specifications.
Retaining serial numbers
This topic provides instructions on the following:
• “Restoring the serial number of the system unit” on page 63
• “Retaining the UUID” on page 63
62 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Restoring the serial number of the system unit
When the computer was manufactured, the EEPROM on the system board was loaded with the serial
numbers of the system and all major components. These numbers need to remain the same throughout the
life of the computer.
If you replace the system board, you must restore the serial number of the system unit to its original value.
The serial number of the system unit is written on the label attached to the bottom of the computer.
If you can not find the serial number of the system unit on the bottom of the computer, try the following
method to get the number:
Note: Before you perform the operation, ensure that the UEFI/Legacy setting within the Startup menu in the
ThinkPad Setup program is set to UEFI Only.
1. Connect a USB memory key to the computer.
2. Go to https://www.lenovo.com/maintenanceutilities and follow the instructions on the screen to create a
Maintenance key.
Note: Only an authorized Lenovo service technician can access the above Web site.
3. Restart the computer.
4. When the logo is displayed, press Esc. The ThinkPad Config Information Update Utility interface is
displayed.
5. Type 1 under Enter the action desired, then press Enter. The ThinkPad Serial Number Update Utility for
Asset ID screen is displayed.
6. Type 2 under Enter the action desired, then press Enter. The serial number of each device in your
computer is displayed; the serial number of the system unit is listed as follow:
20- Serial number
7. Record the serial number of the system unit.
After you replace the system board, do the following to restore the serial number of the system unit:
1. Connect the Maintenance key to the computer.
2. When the logo is displayed, press Esc. The ThinkPad Config Information Update Utility interface is
displayed.
3. Type 1 under Enter the action desired, then press Enter. The ThinkPad Serial Number Update Utility for
Asset ID screen is displayed.
4. Type 1 under Enter the action desired, then press Enter. Then follow the instructions on the screen to
restore the serial number of the system unit.
Retaining the UUID
The Universally Unique Identifier (UUID) is a 128-bit number uniquely assigned to your computer at
production and stored in the EEPROM of your system board.
The algorithm that generates the number is designed to provide unique IDs until the year A.D. 3400. No two
computers in the world have the same number.
When you replace the system board, perform the following steps to create a new UUID for the system board
if the system board does not have a UUID:
Note: Before you perform the operation, ensure that the UEFI/Legacy setting within the Startup menu in the
ThinkPad Setup program is set to UEFI Only.
1. Connect a USB memory key to the computer.
Chapter 7.FRU replacement notices 63
2. Go to https://www.lenovo.com/maintenanceutilities and follow the instructions on the screen to create a
Maintenance key.
Note: Only an authorized Lenovo service technician can access the above Web site.
3. Restart the computer.
4. When the logo screen is displayed, press Esc. The ThinkPad Config Information Update Utility interface
is displayed.
5. Type 2 under Enter the action desired, then press Enter. The Auto UUID generation utility interface is
displayed.
6. Type y under Change UUID. OK? [Y/N], then press Enter. A new UUID is created and written. If a valid
UUID already exists, it is not overwritten.
64 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Chapter 8. Removing or replacing a FRU
This chapter provides instructions on how to remove or replace a FRU.
CRU statement for customers:
You can resolve some problems with your product with a replacement part you can install yourself, called a
“Customer Replaceable Unit” or “CRU.” Some CRUs are designated as self-service CRUs and others are
designated as optional-service CRUs. Installation of self-service CRUs is your responsibility. For optional-
service CRUs, you can either install the CRU yourself or you can request that a Service Provider install the
CRU according to the warranty service for your product. If you intend on installing the CRU, Lenovo will ship
the CRU to you. CRU information and replacement instructions are shipped with your product and are
available from Lenovo at any time upon request. You can find a list of CRUs for your product in this Hardware
Maintenance Manual. An electronic version of this manual can be found at https://support.lenovo.com. Click
Documentation and then follow the on-screen instructions to find the manual for your product. You might be
required to return the defective CRU. When return is required: (1) return instructions, a prepaid shipping label,
and a container will be included with the replacement CRU; and (2) you might be charged for the
replacement CRU if Lenovo does not receive the defective CRU within thirty (30) days of your receipt of the
replacement CRU. See your Lenovo Limited Warranty documentation for full details.
General guidelines
When removing or replacing a FRU, be sure to observe the following general guidelines:
1. Do not try to service any computer unless you have been trained and certified. An untrained person runs
the risk of damaging parts.
2. Before replacing any FRU, review Chapter 7 “FRU replacement notices” on page 61.
3. Begin by removing any FRUs that have to be removed before replacing the failing FRU. Any such FRUs
are listed at the beginning of each FRU replacement procedure. Remove them in the order in which they
are listed.
4. Follow the correct sequence in the steps for removing a FRU, as given in the drawings by the numbers in
square callouts.
5. When turning a screw, turn it in the direction as given by the arrow in the drawing.
6. When removing a FRU, move it in the direction as given by the arrow in the drawing.
7. To put the new FRU in place, reverse the removal procedure and follow any notes that pertain to
replacement. For information about connecting and arranging internal cables, see Chapter 6 “Locations”
on page 45.
8. When replacing a FRU, use the correct screws as shown in the replacement procedure.
DANGER
Before removing any FRU, turn off the computer, unplug all power cords from electrical outlets,
remove the battery pack, and then disconnect any interconnecting cables.
Attention:
• After replacing a FRU, do not turn on the computer until you have made sure that all screws, springs, and
other small parts are in place and none are loose inside the computer. Verify this by shaking the computer
gently and listening for rattling sounds. Metallic parts or metal flakes can cause electrical short circuits.
• The system board is sensitive to, and can be damaged by, ESD. Before touching it, establish personal
grounding by touching a ground point with one hand or by using an ESD strap.
© Copyright Lenovo 2018 65
Disabling the built-in battery
Before replacing any RU, ensure that you disable Fast Startup first and then disable the built-in battery.
To disable Fast Startup, do the following:
1. Go to Control Panel, and then change the view of Control Panel from Category to Large icons or Small
icons.
2. Click Power Options, and then click Choose what the power buttons do on the left pane.
3. Click Change settings that are currently unavailable at the top.
4. If prompted by User Account Control (UAC), click Yes.
5. Clear the Turn on fast startup check box, and then click Save changes.
To disable the built-in battery, do the following:
1. Restart your computer. When the logo screen is displayed, immediately press F1 to enter ThinkPad
Setup.
2. Select Config ➙ Power. The Power submenu is displayed.
3. Select Disable built-in battery and press Enter.
4. Select Yes in the Setup Confirmation window. The built-in battery is disabled and the computer turns off
automatically. Wait three to five minutes to let the computer cool.
1010 MicroSD card
Removal steps of the MicroSD card
Your computer has a microSD card reader that supports the following types of cards:
Note: Your computer does not support the content protection for recordable media (CPRM) feature for the
SD card.
• Secure Digital (SD) card
• Secure Digital High-Capacity (SDHC) card
• Secure Digital eXtended-Capacity (SDXC) card
Attention: During the data transfer, do not put your computer to sleep or hibernation mode before the data
transfer is completed; otherwise, your data could get damaged.
To replace a microSD card, do the following:
1. Locate the microSD card slot at the right side of the computer.
2. Push the microSD card inward a little bit until you hear a click 1. Then, release it. The microSD card
ejects. Gently slide the card out of the card slot 2.
66 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
1020 ThinkPad Pen Pro
Removal steps of the ThinkPad Pen Pro
The ThinkPad Pen Pro is stored in the slot on the bottom side of the computer. To remove the pen from the
slot, slide the tab of the pen a little bit out, and then completely pull out the pen.
1030 Keyboard
Removal steps of the keyboard
a b
Note: If the keyboard must be removed to access other FRUs, you need the keyboard removal tool (product
part number: 01LX856) to remove the keyboard. You can purchase the tool as a separate FRU at: https://
support.lenovo.com/partslookup.
Chapter 8.Removing or replacing a FRU 67
Step Screw (quantity) Color Torque
4M2 × 1.65 mm, flat-head, nylon-coated (2) Silver 0.143 Nm
(1.4 kgf-cm)
c d
68 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Applying labels to the base cover assembly
Note: Depending on the country or region of delivery, the labels might be slightly different from the ones in
the following illustration.
The new base cover FRU is shipped with a kit containing labels of several kinds. Apply those labels when you
replace the base cover. For the labels that are not shipped with the new base cover, peel them from the old
base cover, and adhere them to the new one.
The following illustration shows the location of each label for Windows 10 based computer models.
When you replace the base cover, apply the Serial number label 2.
1 IMEI label 3 GEO label
4 China GEO label 5 CECP (China model) label
6 GML label 7 Country label
8 Asset tag_40Y917Y (available on some models) 9 Asset tag
70 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
1040 Memory module
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
Removal steps of the memory module
Note: A Mylar film might cover the memory module. To access the memory module, open the film first.
When installing:
Insert the notched end of the memory module into the slot at an angle of about 20 degrees. Press the
memory module firmly, and pivot it downwards until it snaps into place. Ensure that the memory module is
firmly installed in the slot and does not move easily.
1060 M.2 solid-state drive
For access, remove this FRU:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
Chapter 8.Removing or replacing a FRU 71
Attention: The M.2 solid-state drive is sensitive. Inappropriate handling might cause damage and
permanent loss of data.
When handling the M.2 solid-state drive, observe the following guidelines:
• Replace the M.2 solid-state drive only for upgrade or repair. The M.2 solid-state drive is not designed for
frequent changes or replacement.
• Before replacing the M.2 solid-state drive, make a backup copy of all the data that you want to keep.
• Do not apply pressure to the M.2 solid-state drive.
• Do not touch the contact edge of the M.2 solid-state drive. Otherwise the M.2 solid-state drive might get
damaged.
• Do not make the M.2 solid-state drive subject to physical shocks or vibration. Put the M.2 solid-state drive
on a soft material, such as cloth, to absorb physical shocks.
Removal steps of the long M.2 solid-state drive
Step Screw (quantity) Color Torque
1M2 × 2 mm, wafer-head, nylon-coated (1) Black 0.181 Nm
(1.85 kgf-cm)
72 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Removal steps of the short M.2 solid-state drive
Step Screw (quantity) Color Torque
1M2 × 2 mm, wafer-head, nylon-coated (1) Black 0.181 Nm
(1.85 kgf-cm)
Step Screw (quantity) Color Torque
3M2 × 2 mm, wafer-head, nylon-coated (1) Black 0.181 Nm
(1.85 kgf-cm)
1070 Coin-cell battery
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
Chapter 8.Removing or replacing a FRU 73
Removal steps of the coin-cell battery
DANGER
Use only the authorized battery specified for your computer. Any other battery could ignite or
explode.
When installing: Ensure that the connector is attached firmly.
1080 Wireless LAN card
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
Removal steps of the wireless LAN card
In step 1, unplug the connectors by using the antenna RF connector removal tool or pick the connectors
with your fingers and gently unplug them as shown.
74 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Step Screw (quantity) Color Torque
2M2 × 2 mm, wafer-head, nylon-coated (1) Black 0.181 Nm
(1.85 kgf-cm)
When installing: Plug the gray cable into the main connector, and the black cable into the auxiliary
connector on the card.
1090 Battery
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
Important notice for replacing a battery
Attention: Lenovo has no responsibility for the performance or safety of unauthorized batteries, and provides no
warranties for failures or damage arising out of their use.
Removal steps of the battery
DANGER
Use only the authorized battery specified for your computer. Any other battery could ignite or
explode.
Chapter 8.Removing or replacing a FRU 75
Step Screw (quantity) Color Torque
2M2 × 4 mm, wafer-head, nylon-coated (5) Black 0.181 Nm
(1.85 kgf-cm)
1100 Speaker assembly
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
76 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Removal steps of the speaker assembly
Step Screw (quantity) Color Torque
4M2 × 4 mm, wafer-head, nylon-coated (2) Black 0.181 Nm
(1.85 kgf-cm)
1110 Trackpad and trackpad cable
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
Chapter 8.Removing or replacing a FRU 77
Removal steps of the trackpad and trackpad cable
Step Screw (quantity) Color Torque
3M2 × 2 mm, fine pitch, wafer-head, nylon-coated (4) Silver 0.181 Nm
(1.85 kgf-cm)
When installing: Ensure that the trackpad is attached firmly.
1120 Wireless LAN antenna assembly
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
78 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
• “1090 Battery” on page 75
• “1100 Speaker assembly” on page 76
Removal steps of the wireless LAN antenna assembly
Release the antenna cables from the cable guides on the LCD cover assembly.
Attention: When you route the cables, ensure that they are not subject to any tension. Tension could cause
the cables to be damaged by the cable guides, or a wire to be broken.
Chapter 8.Removing or replacing a FRU 79
Antenna locations
a Wireless-LAN main antenna (gray)
b Wireless-LAN auxiliary antenna (black)
1130 ThinkPad Pen Pro charger with cable
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
• “1100 Speaker assembly” on page 76
• “1120 Wireless LAN antenna assembly” on page 78
80 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Removal steps of the ThinkPad Pen Pro charger with cable
Step Screw (quantity) Color Torque
3M2 × 4 mm, wafer-head, nylon-coated (1) Black 0.181 Nm
(1.85 kgf-cm)
When installing: Ensure that the connector is attached firmly to the system board.
1140 Power button board with cable
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
• “1100 Speaker assembly” on page 76
• “1120 Wireless LAN antenna assembly” on page 78
• “1130 ThinkPad Pen Pro charger with cable” on page 80
Chapter 8.Removing or replacing a FRU 81
Removal steps of the power button board with cable
Step Screw (quantity) Color Torque
3M2 × 4 mm, wafer-head, nylon-coated (1) Black 0.181 Nm
(1.85 kgf-cm)
1150 NFC board with cable, NFC attenna
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
• “1100 Speaker assembly” on page 76
82 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Removal steps of the NFC board with cable, NFC attenna
When installing: Ensure that the connector is attached firmly to the system board.
1160 Fingerprint reader bracket and fingerprint reader with cable
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
• “1100 Speaker assembly” on page 76
Chapter 8.Removing or replacing a FRU 83
Removal steps of the fingerprint reader bracket and fingerprint reader with cable
Step Screw (quantity) Color Torque
1M2 × 2.5 mm, wafer-head, nylon-coated (2) Black 0.181 Nm
(1.85 kgf-cm)
When installing: Ensure that the connectors are attached firmly.
1170 Rear camera board with cable
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
84 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Removal steps of the rear camera board with cable
When installing: Ensure that the connector is attached firmly to the system board.
1180 LCD unit
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
Removal steps of the LCD unit
Note: The computer that you are servicing might be different from the one in the following illustrations.
Chapter 8.Removing or replacing a FRU 85
Step Screw (quantity) Color Torque
3M 2.5 × 4.5 mm, wafer-head, nylon-coated (6) Silver 0.294 Nm
(3.0 kgf-cm)
86 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Removal steps of the HDMI connector bracket
Step Screw (quantity) Color Torque
1M 2 x 4 mm, wafer-head, nylon-coated (2) Black 0.181 Nm
(1.85 kgf-cm)
1200 USB 3.1 connector bracket
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
• “1180 LCD unit” on page 85
Removal steps of the USB 3.1 connector bracket
Step Screw (quantity) Color Torque
1M 2 x 4 mm, wafer-head, nylon-coated (2) Black 0.181 Nm
(1.85 kgf-cm)
1210 Thermal fan
For access, remove these FRUs in order:
88 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
Removal steps of the thermal fan
When installing:
• Ensure that the connector is attached firmly.
• Do not press the top of the fan cover and the fan hub.
• Before you attach the fan assembly to the computer, apply thermal grease, at an amount of 0.2 grams, on
the part marked a as shown in the following illustrations. Either too much or too less application of grease
can cause a thermal problem due to imperfect contact with a component.
Chapter 8.Removing or replacing a FRU 89
1220 System board
Important notices for handling the system board:
When handling the system board, read the following:
• The system board has an accelerometer, which can be broken when several thousands of G-forces are applied.
Note: Dropping a system board from a height of as little as 6 inches so that it falls flat on a hard bench can subject
the accelerometer to as much as 6000 G's of shock.
• Be careful not to drop the system board on a bench top that has a hard surface, such as metal, wood, or
composite.
• Avoid rough handling of any kind.
• At every point in the process, be sure not to drop or stack the system board.
• If you put a system board down, be sure to put it only on a padded surface such as an ESD mat or a corrugated
conductive surface.
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Keyboard” on page 67
Note: The keyboard removal tool (product part number: 01LX856) is needed for removing the keyboard.
You can purchase it as a separate FRU at: https://support.lenovo.com/partslookup.
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
• “1040 Memory module” on page 71
• “1060 M.2 solid-state drive” on page 71
• “1100 Speaker assembly” on page 76
• “1070 Coin-cell battery” on page 73
• “1080 Wireless LAN card” on page 74
• “1210 Thermal fan” on page 88
Attention: The following components soldered on the top side of the system board are extremely sensitive.
When you service the system board, avoid any kind of rough handling.
a Microprocessor
90 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Step Screw (quantity) Color Torque
6M 2 x 4 mm, wafer-head, nylon-coated (4) Black 0.181 Nm
(1.85 kgf-cm)
92 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Step Screw (quantity) Color Torque
8M 2 x 2.5 mm, wafer-head, nylon-coated (4) Black 0.181 Nm
(1.85 kgf-cm)
When installing: Ensure that the connectors are attached firmly.
1230 Keyboard bezel assembly
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Keyboard” on page 67
Note: The keyboard removal tool (product part number: 01LX856) is needed for removing the keyboard.
You can purchase it as a separate FRU at: https://support.lenovo.com/partslookup.
• “1030 Base cover assembly” on page 69
• “1040 Memory module” on page 71
• “1060 M.2 solid-state drive” on page 71
• “1070 Coin-cell battery” on page 73
• “1080 Wireless LAN card” on page 74
• “1020 ThinkPad Pen Pro” on page 67
• “1090 Battery” on page 75
• “1210 Thermal fan” on page 88
• “1110 Trackpad and trackpad cable” on page 77
• “1120 Wireless LAN antenna assembly” on page 78
• “1130 ThinkPad Pen Pro charger with cable” on page 80
• “1140 Power button board with cable” on page 81
• “1100 Speaker assembly” on page 76
• “1160 Fingerprint reader bracket and fingerprint reader with cable” on page 83
• “1170 Rear camera board with cable” on page 84
• “1180 LCD unit” on page 85
• “1190 HDMI connector bracket” on page 87
• “1200 USB 3.1 connector bracket” on page 88
• “1220 System board ” on page 90
Removal steps of the keyboard bezel assembly
LCD FRUs for Yoga models
This chapter provides information about replacement of LCD FRUs for Yoga models.
Chapter 8.Removing or replacing a FRU 93
2010 Strip cover and rubber caps
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
• “1180 LCD unit” on page 85
Removal steps of the strip cover and rubber caps
Step Screw (quantity) Color Torque
1M2 × 4 mm, wafer-head, nylon-coated (2) Black 0.181 Nm
(1.85 kgf-cm)
When installing: Ensure that all the latches are attached firmly.
2020 Touch module assembly and hinge rubber
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
• “1180 LCD unit” on page 85
• “2010 Strip cover and rubber caps” on page 94
94 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Step Screw (quantity) Color Torque
4M 2 × 3 mm, wafer-head, nylon-coated, small head (4) Black 0.181 Nm
(1.85 kgf-cm)
When installing: Ensure that the LCD connector is attached firmly.
2030 LCD hinges
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
• “1180 LCD unit” on page 85
• “2010 Strip cover and rubber caps” on page 94
• “2020 Touch module assembly and hinge rubber” on page 94
96 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Removal steps of the LCD hinges
Step Screw (quantity) Color Torque
1M 2.5 × 2.5 mm, wafer-head, nylon-coated (6) Black 0.294 Nm
(3.0 kgf-cm)
2040 LCD cable and touch control board
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
• “1180 LCD unit” on page 85
• “2010 Strip cover and rubber caps” on page 94
• “2020 Touch module assembly and hinge rubber” on page 94
• “2030 LCD hinges” on page 96
Removal steps of the LCD cable and touch control board
Chapter 8.Removing or replacing a FRU 97
Attention: When you route the cables, ensure that they are not subject to any tension. Tension could cause
the cables to be damaged by the cable guides, or a wire to be broken.
2050 Infrared camera/microphone module with cable
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
• “1180 LCD unit” on page 85
• “2010 Strip cover and rubber caps” on page 94
• “2020 Touch module assembly and hinge rubber” on page 94
Removal steps of the infrared camera/microphone module
98 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
When installing: Ensure that the connector is attached firmly.
2060 Sensor board with cable and LCD rear cover assembly
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
• “1180 LCD unit” on page 85
• “2010 Strip cover and rubber caps” on page 94
• “2020 Touch module assembly and hinge rubber” on page 94
Removal steps of the sensor board for computer models with infrared camera
100 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Removal steps of the sensor board cable and LCD cover assembly
When installing: Ensure that the connector is attached firmly.
2070 ThinkPad-logo-LED card with cable
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
• “1180 LCD unit” on page 85
• “2010 Strip cover and rubber caps” on page 94
• “2020 Touch module assembly and hinge rubber” on page 94
Removal steps of the ThinkPad-logo-LED card with cable
LCD FRUs for non-yoga models
This chapter provides information about replacement of LCD FRUs for non-yoga models.
2080 LCD bezel
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
• “1180 LCD unit” on page 85
102 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Removal steps of the LCD bezel
When installing: Ensure that all the latches are attached firmly.
2090 LCD panel and LCD cable
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
• “1180 LCD unit” on page 85
• “2080 LCD bezel” on page 102
Removal steps of the LCD panel and LCD cable
Step Screw (quantity) Color Torque
1M2 × 2.5 mm, wafer-head, nylon-coated, small head (4) Black 0.181 Nm
(1.85 kgf-cm)
Chapter 8.Removing or replacing a FRU 103
When installing: Ensure that the LCD connector is attached firmly.
2100 LCD hinges
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
• “1180 LCD unit” on page 85
• “2080 LCD bezel” on page 102
• “2090 LCD panel and LCD cable ” on page 103
Removal steps of the LCD hinges
Step Screw (quantity) Color Torque
1M2.5 × 2.5 mm, wafer-head, nylon-coated (6) Black 0.294 Nm
(3.0 kgf-cm)
104 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
2110 RGB camera/microphone module with cable and LCD rear cover
assembly
For access, remove these FRUs in order:
• “1020 ThinkPad Pen Pro” on page 67
• “1030 Base cover assembly” on page 69
• “1090 Battery” on page 75
• “1180 LCD unit” on page 85
• “2080 LCD bezel” on page 102
• “2090 LCD panel and LCD cable ” on page 103
• “2100 LCD hinges” on page 104
Removal steps of the RGB camera/microphone module
Chapter 8.Removing or replacing a FRU 105
Removal steps of the RGB camera/microphone module/ThinkPad-logo-LED card cable and the LCD
rear cover assembly
When installing: Ensure that the connector is attached firmly.
106 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Appendix A. Notices
Lenovo may not offer the products, services, or features discussed in this document in all countries. Consult
your local Lenovo representative for information on the products and services currently available in your
area. Any reference to a Lenovo product, program, or service is not intended to state or imply that only that
Lenovo product, program, or service may be used. Any functionally equivalent product, program, or service
that does not infringe any Lenovo intellectual property right may be used instead. However, it is the user’s
responsibility to evaluate and verify the operation of any other product, program, or service.
Lenovo may have patents or pending patent applications covering subject matter described in this
document. The furnishing of this document does not give you any license to these patents. You can send
license inquiries, in writing, to:
Lenovo (United States), Inc.
1009 Think Place - Building One
Morrisville, NC 27560
U.S.A.
Attention: Lenovo Director of Licensing
LENOVO PROVIDES THIS PUBLICATION “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF NON-INFRINGEMENT,
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Some jurisdictions do not allow
disclaimer of express or implied warranties in certain transactions, therefore, this statement may not apply to
you.
This information could include technical inaccuracies or typographical errors. Changes are periodically made
to the information herein; these changes will be incorporated in new editions of the publication. Lenovo may
make improvements and/or changes in the product(s) and/or the program(s) described in this publication at
any time without notice.
The products described in this document are not intended for use in implantation or other life support
applications where malfunction may result in injury or death to persons. The information contained in this
document does not affect or change Lenovo product specifications or warranties. Nothing in this document
shall operate as an express or implied license or indemnity under the intellectual property rights of Lenovo or
third parties. All information contained in this document was obtained in specific environments and is
presented as an illustration. The result obtained in other operating environments may vary.
Lenovo may use or distribute any of the information you supply in any way it believes appropriate without
incurring any obligation to you.
Any references in this publication to non-Lenovo Web sites are provided for convenience only and do not in
any manner serve as an endorsement of those Web sites. The materials at those Web sites are not part of the
materials for this Lenovo product, and use of those Web sites is at your own risk.
Any performance data contained herein was determined in a controlled environment. Therefore, the result
obtained in other operating environments may vary significantly. Some measurements may have been made
on development-level systems and there is no guarantee that these measurements will be the same on
generally available systems. Furthermore, some measurements may have been estimated through
extrapolation. Actual results may vary. Users of this document should verify the applicable data for their
specific environment.
© Copyright Lenovo 2018 107
Electromagnetic emission notices
For electromagnetic emission information on Class B digital devices, refer to the corresponding information
in the User Guide.
EU contact: Lenovo, Einsteinova 21, 851 01 Bratislava, Slovakia
Trademarks
Trademarks
LENOVO, LENOVO logo, THINKPAD, THINKPAD logo, TRACKPOINT, ULTRACONNECT, and Yoga are
trademarks of Lenovo. Microsoft, Windows, Direct3D, BitLocker, and Cortana are trademarks of the
Microsoft group of companies. Ubuntu is a registered trademark of Canonical Ltd. The terms HDMI and
HDMI High-Definition Multimedia Interface are trademarks or registered trademarks of HDMI Licensing LLC
in the United States and other countries. Wi-Fi, Wi-Fi Alliance, and Miracast are registered trademarks of Wi-
Fi Alliance. USB-C is a trademark of USB Implementers Forum. All other trademarks are the property of their
respective owners. © 2018 Lenovo.
108 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Appendix B. Abbreviation and acronym table
The following table lists some abbreviations and acronyms which might be used in this manual.
Abbreviation Term
BGA Ball Grid Array
BIOS basic input/output system
CMOS complementary metal-oxide semiconductor
COA Certificate of Authentication
CRC cyclic redundancy check
CRT cathode ray tube
CRU customer-replaceable unit
CTO Configure To Order
EAIA Enhanced Asset Information Area
ECA Engineering Change Announcements
EEPROM Electrically Erasable Programmable Read-Only Memory
EFI Extensible Firmware Interface
EPO emergency power-off
ESD electrostatic discharge
EU European Union
FCC Federal Communications Commission
FRU Field Replaceable Unit
GAV General Announce Variant
GPU graphics processing unit
HDD hard disk drive
HDMI high-definition multimedia interface
ICs integrated circuits
ICCID integrate circuit card identity
ISO International Standardization Organization
LAN local area network
LCD liquid crystal display
MAC media access control
MT machine type
MTM machine type and model
PC personal computer
PCH Platform Controller Hub
POST power-on self-test
© Copyright Lenovo 2018 109
Abbreviation Term
RAM random-access memory
RF radio frequency
RFID radio-frequency identification
RI ring indicator
RJ registered jack
SATA Serial Advanced Technology Attachment
SIM subscriber identity module
SVP supervisor password
TFTs thin-film transistors
UEFI Unified Extensible Firmware Interface
USB Universal Serial Bus
UUID universally unique identifier
VGA video graphics array
VRAM video random-access memory
WAN wide area network
110 L390, L390 Yoga, S2 4th Gen, and S2 Yoga 4th Gen Hardware Maintenance Manual
Part Number: SP40G76717
Printed in China
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