Table of Contents
- Latitude 7420 Service Manual
- Contents
- Working on your computer
- Removing and installing components
- Recommended tools
- Screw List
- Major components of your system
- micro-SD card
- SIM card tray
- Base cover
- Solid-state drive
- WWAN card
- Battery
- Heatsink assembly
- Palmrest antenna module
- Display assembly
- Audio board
- Speakers
- SmartCard reader
- System board
- I/O board
- Power button with fingerprint reader
- Keyboard
- Palmrest assembly
- Software
- BIOS setup
- Troubleshooting
- Handling swollen Lithium-ion batteries
- Dell SupportAssist Pre-boot System Performance Check diagnostics
- Built-in self-test (BIST)
- System-diagnostic lights
- Recovering the operating system
- Real-Time Clock (RTC Reset)
- Backup media and recovery options
- WiFi power cycle
- Drain residual flea power (perform hard reset)
- Getting help and contacting Dell
DELL 7420 User Manual
Displayed below is the user manual for 7420 by DELL which is a product in the Notebooks category. This manual has pages.
Related Manuals
Latitude 7420
Service Manual
Regulatory Model: P135G/P136G
Regulatory Type: P135G001/P136G001
August 2021
Rev. A02
Notes, cautions, and warnings
NOTE: A NOTE indicates important information that helps you make better use of your product.
CAUTION: A CAUTION indicates either potential damage to hardware or loss of data and tells you how to avoid
the problem.
WARNING: A WARNING indicates a potential for property damage, personal injury, or death.
© 2021 Dell Inc. or its subsidiaries. All rights reserved. Dell, EMC, and other trademarks are trademarks of Dell Inc. or its subsidiaries. Other
trademarks may be trademarks of their respective owners.
Chapter 1: Working on your computer........................................................................................... 6
Safety instructions.............................................................................................................................................................. 6
Service mode.................................................................................................................................................................. 6
Before working inside your computer.......................................................................................................................8
Safety precautions........................................................................................................................................................ 9
Electrostatic discharge—ESD protection............................................................................................................... 9
ESD field service kit ................................................................................................................................................... 10
Transporting sensitive components......................................................................................................................... 11
After working inside your computer......................................................................................................................... 11
Chapter 2: Removing and installing components.......................................................................... 12
Recommended tools..........................................................................................................................................................12
Screw List............................................................................................................................................................................ 12
Major components of your system................................................................................................................................ 15
micro-SD card.....................................................................................................................................................................16
Removing the micro-SD card....................................................................................................................................16
Installing the micro-SD card...................................................................................................................................... 17
SIM card tray.......................................................................................................................................................................17
Removing the SIM card tray......................................................................................................................................17
Installing the SIM card tray........................................................................................................................................18
Base cover........................................................................................................................................................................... 19
Removing the base cover...........................................................................................................................................19
Installing the base cover.............................................................................................................................................21
Solid-state drive................................................................................................................................................................ 22
Removing the solid-state drive................................................................................................................................ 22
Installing the solid-state drive.................................................................................................................................. 23
WWAN card........................................................................................................................................................................ 24
Removing the WWAN card....................................................................................................................................... 24
Installing the WWAN card......................................................................................................................................... 26
Battery................................................................................................................................................................................. 27
Lithium-ion battery precautions...............................................................................................................................27
Removing the 3-cell battery..................................................................................................................................... 27
Installing the 3-cell battery....................................................................................................................................... 28
Removing the 4-cell battery..................................................................................................................................... 30
Installing the 4-cell battery........................................................................................................................................ 31
Heatsink assembly.............................................................................................................................................................32
Removing the heatsink assembly.............................................................................................................................32
Installing the heatsink assembly...............................................................................................................................33
Palmrest antenna module................................................................................................................................................33
Removing the palmrest antenna module............................................................................................................... 33
Installing the palmrest antenna module..................................................................................................................34
Display assembly................................................................................................................................................................35
Removing the display assembly............................................................................................................................... 35
Installing the display assembly..................................................................................................................................38
Contents
Contents 3
Audio board.........................................................................................................................................................................40
Removing the audio board........................................................................................................................................ 40
Installing the audio board........................................................................................................................................... 41
Speakers.............................................................................................................................................................................. 42
Removing the speakers..............................................................................................................................................42
Installing the speaker.................................................................................................................................................. 43
SmartCard reader..............................................................................................................................................................44
Removing the smart card reader............................................................................................................................. 44
Installing the smart card reader............................................................................................................................... 46
System board......................................................................................................................................................................47
Removing the system board..................................................................................................................................... 47
Installing the system board....................................................................................................................................... 49
I/O board.............................................................................................................................................................................52
Removing the I/O board............................................................................................................................................52
Installing the I/O board.............................................................................................................................................. 52
Power button with fingerprint reader.......................................................................................................................... 53
Removing the power button with fingerprint reader..........................................................................................53
Installing the power button with fingerprint reader............................................................................................54
Keyboard............................................................................................................................................................................. 55
Removing the keyboard............................................................................................................................................. 55
Installing the keyboard............................................................................................................................................... 57
Palmrest assembly............................................................................................................................................................ 59
Removing the palmrest assembly............................................................................................................................59
Installing the palmrest assembly.............................................................................................................................. 60
Chapter 3: Software.................................................................................................................... 62
Operating system.............................................................................................................................................................. 62
Drivers and downloads..................................................................................................................................................... 62
Chapter 4: BIOS setup.................................................................................................................63
BIOS overview................................................................................................................................................................... 63
Entering BIOS setup program........................................................................................................................................ 63
Navigation keys..................................................................................................................................................................63
One time boot menu.........................................................................................................................................................64
System setup options.......................................................................................................................................................64
Updating the BIOS............................................................................................................................................................ 74
Updating the BIOS in Windows................................................................................................................................ 74
Updating the BIOS in Linux and Ubuntu................................................................................................................ 75
Updating the BIOS using the USB drive in Windows..........................................................................................75
Updating the BIOS from the F12 One-Time boot menu.....................................................................................75
System and setup password...........................................................................................................................................76
Assigning a system setup password....................................................................................................................... 76
Deleting or changing an existing system setup password................................................................................. 77
Clearing BIOS (System Setup) and System passwords...........................................................................................77
Chapter 5: Troubleshooting......................................................................................................... 78
Handling swollen Lithium-ion batteries........................................................................................................................ 78
Dell SupportAssist Pre-boot System Performance Check diagnostics................................................................79
Running the SupportAssist Pre-Boot System Performance Check................................................................79
4Contents
Built-in self-test (BIST)................................................................................................................................................... 79
M-BIST........................................................................................................................................................................... 79
LCD Power rail test (L-BIST)................................................................................................................................... 80
LCD Built-in Self Test (BIST)................................................................................................................................... 80
System-diagnostic lights.................................................................................................................................................. 81
Recovering the operating system................................................................................................................................. 82
Real-Time Clock (RTC Reset)........................................................................................................................................82
Backup media and recovery options.............................................................................................................................83
WiFi power cycle............................................................................................................................................................... 83
Drain residual flea power (perform hard reset)......................................................................................................... 83
Chapter 6: Getting help and contacting Dell................................................................................ 85
Contents 5
Working on your computer
Topics:
•Safety instructions
Safety instructions
Use the following safety guidelines to protect your computer from potential damage and to ensure your personal safety. Unless
otherwise noted, each procedure included in this document assumes that you have read the safety information that shipped
with your computer.
WARNING: Before working inside your computer, read the safety information that is shipped with your
computer. For more safety best practices, see the Regulatory Compliance home page at www.dell.com/
regulatory_compliance.
WARNING: Disconnect your computer from all power sources before opening the computer cover or panels.
After you finish working inside the computer, replace all covers, panels, and screws before connecting your
computer to an electrical outlet.
CAUTION: To avoid damaging the computer, ensure that the work surface is flat, dry, and clean.
CAUTION: To avoid damaging the components and cards, handle them by their edges, and avoid touching the
pins and the contacts.
CAUTION: You should only perform troubleshooting and repairs as authorized or directed by the Dell technical
assistance team. Damage due to servicing that is not authorized by Dell is not covered by your warranty. See the
safety instructions that is shipped with the product or at www.dell.com/regulatory_compliance.
CAUTION: Before touching anything inside your computer, ground yourself by touching an unpainted metal
surface, such as the metal at the back of the computer. While you work, periodically touch an unpainted metal
surface to dissipate static electricity which could harm internal components.
CAUTION: When you disconnect a cable, pull it by its connector or its pull tab, not the cable itself. Some cables
have connectors with locking tabs or thumbscrews that you must disengage before disconnecting the cable.
When disconnecting cables, keep them evenly aligned to avoid bending the connector pins. When connecting
cables, ensure that the ports and the connectors are correctly oriented and aligned.
CAUTION: Press and eject any installed card from the media-card reader.
CAUTION: Exercise caution when handling Lithium-ion batteries in laptops. Swollen batteries should not be used
and should be replaced and disposed properly.
NOTE: The color of your computer and certain components may appear differently than shown in this document.
Service mode
Service Mode allows users to immediately cut off power from the system and conduct repairs without disconnecting the
battery cable from the system board:
1. Shut down the system and disconnect the AC adapter.
2. Press and hold the <B> key on the keyboard and then press the power button. The system boots.
1
6 Working on your computer
3. [For models configured with an Owner Tag] When the Owner Tag information appears on the screen, press any key to
proceed.
NOTE: The Service Mode procedure will automatically skip this step if the Owner Tag of the system is not set up in
advance by the manufacturer.
4. Ensure that the AC adapter has been disconnected and press any key to proceed.
Working on your computer 7
5. When the ready-to-proceed message appears on the screen, press any key to proceed. The system emits three short beeps
and shuts down immediately.
Once the system shuts down, you can perform replacement procedures without disconnecting the battery cable from the
system board.
To exit Service Mode, connect AC adapter and press the power button to power on the system. The system will automatically
return to normal functioning mode.
Before working inside your computer
About this task
NOTE: The images in this document may differ from your computer depending on the configuration you ordered.
Steps
1. Save and close all open files and exit all open applications.
2. Shut down your computer. Click Start > Power > Shut down.
NOTE: If you are using a different operating system, see the documentation of your operating system for shut-down
instructions.
3. Disconnect your computer and all attached devices from their electrical outlets.
8Working on your computer
4. Disconnect all attached network devices and peripherals, such as keyboard, mouse, and monitor from your computer.
CAUTION: To disconnect a network cable, first unplug the cable from your computer and then unplug the
cable from the network device.
5. Remove any media card and optical disc from your computer, if applicable.
Safety precautions
The safety precautions chapter details the primary steps to be taken before performing any disassembly instructions.
Observe the following safety precautions before you perform any installation or break/fix procedures involving disassembly or
reassembly:
●Turn off the system and all attached peripherals.
●Disconnect the system and all attached peripherals from AC power.
●Disconnect all network cables, telephone, and telecommunications lines from the system.
●Use an ESD field service kit when working inside any notebook to avoid electrostatic discharge (ESD) damage.
●After removing any system component, carefully place the removed component on an anti-static mat.
●Wear shoes with non-conductive rubber soles to reduce the chance of getting electrocuted.
Standby power
Dell products with standby power must be unplugged before you open the case. Systems that incorporate standby power are
essentially powered while turned off. The internal power enables the system to be remotely turned on (wake on LAN) and
suspended into a sleep mode and has other advanced power management features.
Unplugging, pressing and holding the power button for 20 seconds should discharge residual power in the system board.
Remove the battery from notebooks.
Bonding
Bonding is a method for connecting two or more grounding conductors to the same electrical potential. This is done through
the use of a field service electrostatic discharge (ESD) kit. When connecting a bonding wire, ensure that it is connected to bare
metal and never to a painted or non-metal surface. The wrist strap should be secure and in full contact with your skin, and
ensure that you remove all jewelry such as watches, bracelets, or rings prior to bonding yourself and the equipment.
Electrostatic discharge—ESD protection
ESD is a major concern when you handle electronic components, especially sensitive components such as expansion cards,
processors, memory DIMMs, and system boards. Very slight charges can damage circuits in ways that may not be obvious, such
as intermittent problems or a shortened product life span. As the industry pushes for lower power requirements and increased
density, ESD protection is an increasing concern.
Due to the increased density of semiconductors used in recent Dell products, the sensitivity to static damage is now higher than
in previous Dell products. For this reason, some previously approved methods of handling parts are no longer applicable.
Two recognized types of ESD damage are catastrophic and intermittent failures.
●Catastrophic – Catastrophic failures represent approximately 20 percent of ESD-related failures. The damage causes
an immediate and complete loss of device functionality. An example of catastrophic failure is a memory DIMM that has
received a static shock and immediately generates a "No POST/No Video" symptom with a beep code emitted for missing or
nonfunctional memory.
●Intermittent – Intermittent failures represent approximately 80 percent of ESD-related failures. The high rate of
intermittent failures means that most of the time when damage occurs, it is not immediately recognizable. The DIMM
receives a static shock, but the tracing is merely weakened and does not immediately produce outward symptoms related to
the damage. The weakened trace may take weeks or months to melt, and in the meantime may cause degradation of memory
integrity, intermittent memory errors, etc.
The more difficult type of damage to recognize and troubleshoot is the intermittent (also called latent or "walking wounded")
failure.
Perform the following steps to prevent ESD damage:
Working on your computer 9
●Use a wired ESD wrist strap that is properly grounded. The use of wireless anti-static straps is no longer allowed; they do not
provide adequate protection. Touching the chassis before handling parts does not ensure adequate ESD protection on parts
with increased sensitivity to ESD damage.
●Handle all static-sensitive components in a static-safe area. If possible, use anti-static floor pads and workbench pads.
●When unpacking a static-sensitive component from its shipping carton, do not remove the component from the anti-static
packing material until you are ready to install the component. Before unwrapping the anti-static packaging, ensure that you
discharge static electricity from your body.
●Before transporting a static-sensitive component, place it in an anti-static container or packaging.
ESD field service kit
The unmonitored Field Service kit is the most commonly used service kit. Each Field Service kit includes three main components:
anti-static mat, wrist strap, and bonding wire.
Components of an ESD field service kit
The components of an ESD field service kit are:
●Anti-Static Mat – The anti-static mat is dissipative and parts can be placed on it during service procedures. When using an
anti-static mat, your wrist strap should be snug and the bonding wire should be connected to the mat and to any bare metal
on the system being worked on. Once deployed properly, service parts can be removed from the ESD bag and placed directly
on the mat. ESD-sensitive items are safe in your hand, on the ESD mat, in the system, or inside a bag.
●Wrist Strap and Bonding Wire – The wrist strap and bonding wire can be either directly connected between your wrist
and bare metal on the hardware if the ESD mat is not required, or connected to the anti-static mat to protect hardware that
is temporarily placed on the mat. The physical connection of the wrist strap and bonding wire between your skin, the ESD
mat, and the hardware is known as bonding. Use only Field Service kits with a wrist strap, mat, and bonding wire. Never
use wireless wrist straps. Always be aware that the internal wires of a wrist strap are prone to damage from normal wear
and tear, and must be checked regularly with a wrist strap tester in order to avoid accidental ESD hardware damage. It is
recommended to test the wrist strap and bonding wire at least once per week.
●ESD Wrist Strap Tester – The wires inside of an ESD strap are prone to damage over time. When using an unmonitored
kit, it is a best practice to regularly test the strap prior to each service call, and at a minimum, test once per week. A
wrist strap tester is the best method for doing this test. If you do not have your own wrist strap tester, check with your
regional office to find out if they have one. To perform the test, plug the wrist-strap's bonding-wire into the tester while it is
strapped to your wrist and push the button to test. A green LED is lit if the test is successful; a red LED is lit and an alarm
sounds if the test fails.
●Insulator Elements – It is critical to keep ESD sensitive devices, such as plastic heat sink casings, away from internal parts
that are insulators and often highly charged.
●Working Environment – Before deploying the ESD Field Service kit, assess the situation at the customer location. For
example, deploying the kit for a server environment is different than for a desktop or portable environment. Servers are
typically installed in a rack within a data center; desktops or portables are typically placed on office desks or cubicles. Always
look for a large open flat work area that is free of clutter and large enough to deploy the ESD kit with additional space to
accommodate the type of system that is being repaired. The workspace should also be free of insulators that can cause an
ESD event. On the work area, insulators such as Styrofoam and other plastics should always be moved at least 12 inches or
30 centimeters away from sensitive parts before physically handling any hardware components
●ESD Packaging – All ESD-sensitive devices must be shipped and received in static-safe packaging. Metal, static-shielded
bags are preferred. However, you should always return the damaged part using the same ESD bag and packaging that the
new part arrived in. The ESD bag should be folded over and taped shut and all the same foam packing material should be
used in the original box that the new part arrived in. ESD-sensitive devices should be removed from packaging only at an
ESD-protected work surface, and parts should never be placed on top of the ESD bag because only the inside of the bag is
shielded. Always place parts in your hand, on the ESD mat, in the system, or inside an anti-static bag.
●Transporting Sensitive Components – When transporting ESD sensitive components such as replacement parts or parts
to be returned to Dell, it is critical to place these parts in anti-static bags for safe transport.
ESD protection summary
It is recommended that all field service technicians use the traditional wired ESD grounding wrist strap and protective anti-static
mat at all times when servicing Dell products. In addition, it is critical that technicians keep sensitive parts separate from all
insulator parts while performing service and that they use anti-static bags for transporting sensitive components.
10 Working on your computer
Transporting sensitive components
When transporting ESD sensitive components such as replacement parts or parts to be returned to Dell, it is critical to place
these parts in anti-static bags for safe transport.
After working inside your computer
About this task
NOTE: Leaving stray or loose screws inside your computer may severely damage your computer.
Steps
1. Replace all screws and ensure that no stray screws remain inside your computer.
2. Connect any external devices, peripherals, or cables you removed before working on your computer.
3. Replace any media cards, discs, or any other parts that you removed before working on your computer.
4. Connect your computer and all attached devices to their electrical outlets.
5. Turn on your computer.
Working on your computer 11
Removing and installing components
NOTE: The images in this document may differ from your computer depending on the configuration you ordered.
Topics:
•Recommended tools
•Screw List
•Major components of your system
•micro-SD card
•SIM card tray
•Base cover
•Solid-state drive
•WWAN card
•Battery
•Heatsink assembly
•Palmrest antenna module
•Display assembly
•Audio board
•Speakers
•SmartCard reader
•System board
•I/O board
•Power button with fingerprint reader
•Keyboard
•Palmrest assembly
Recommended tools
The procedures in this document require the following tools:
●Phillips #0 screwdriver
●Phillips #1 screwdriver
●Plastic scribe
Screw List
The following table shows the screw list and the image of the screws.
2
12 Removing and installing components
Table 1. Screw list
Component Screw type Quantity Image
Base cover Captive screws
NOTE: Screws are
part of the base
cover.
8
Solid-state drive M2x2 2
WWAN M2x2.5 1
3-cell Battery M2.5x4
Captive screws
1
4
4-cell Battery M2x4
Captive screws
1
4
Heatsink assembly M2x2.5 6
Palmrest antenna M2x2
M2x2.5
1
2
Display assembly M2x2
M2.5x5
3
4
Audio board M2x2.5 1
SmartCard reader M2x2.5 4
System board M2x2
M2x2.5
M2x3
M2x4
3
4
2
2
I/O board M2x4 2
Removing and installing components 13
Table 1. Screw list (continued)
Component Screw type Quantity Image
Power button with fingerprint reader M1.6x1.7 2
Keyboard M1.6x1.7
M2x2
26
2
14 Removing and installing components
Major components of your system
1. Base cover
Removing and installing components 15
2. Battery
3. I/O board
4. Heatsink
5. Solid-state drive cover
6. System board
7. Speakers
8. Audio board
9. Palmrest assembly
10. Display assembly
11. Keyboard assembly
12. Power button with fingerprint reader
13. SmartCard reader
14. Palmrest antenna
15. WWAN card shield
16. Solid-state drive
17. Solid-state drive shield
18. WWAN card
NOTE: Dell provides a list of components and their part numbers for the original system configuration purchased. These
parts are available according to warranty coverages purchased by the customer. Contact your Dell sales representative for
purchase options.
micro-SD card
Removing the micro-SD card
About this task
The following images indicate the location of the micro-SD card reader slot and provide a visual representation of the removal
procedure.
Steps
1. Push the micro-SD card to eject it from the slot.
2. Remove the micro-SD card from the computer.
16 Removing and installing components
Installing the micro-SD card
Prerequisites
If you are replacing a component, remove the existing component before performing the installation procedure.
About this task
The following image indicates the location of the micro-SD card reader slot and provides a visual representation of the
installation procedure.
Steps
Insert the micro-SD card into its slot until it clicks into place.
SIM card tray
Removing the SIM card tray
Prerequisites
Follow the procedure in before working inside your computer.
About this task
The following image provides a visual representation of the SIM card tray removal procedure.
Removing and installing components 17
Steps
1. Insert a pin into the release hole to release the SIM card tray.
2. Push the pin to disengage the lock, and eject the SIM card tray.
3. Slide the SIM card tray out of the slot on the system.
4. Remove the SIM card from the SIM card tray.
5. Slide and push the SIM card tray back into the slot.
Installing the SIM card tray
Prerequisites
If you are replacing a component, remove the necessary component before the installation procedure.
About this task
The following image provides a visual representation of the SIM card tray installation procedure.
18 Removing and installing components
Steps
1. Align and place the SIM card in the dedicated slot on the SIM card tray.
2. Slide the SIM card tray into the slot in the system [6], and push it to lock in place.
Next steps
Follow the procedure in After working on your computer.
Base cover
Removing the base cover
Prerequisites
1. Follow the procedure in before working inside your computer.
2. Remove the microSD card.
3. Enter the service mode.
Removing and installing components 19
About this task
20 Removing and installing components
Steps
1. Loosen the eight captive screws that secure the base cover to the computer.
2. Use a plastic scribe to pry open the base cover, starting from the U-shaped recesses near the hinges at the top edge of the
base cover.
CAUTION: Do not slide the scribe through the edge of the top side of the base cover as it damages the
latches inside the base cover.
3. Pry open the left and right sides of the base cover.
4. Pry open the bottom side of the base cover.
5. Hold the left and right sides of the base cover and remove it from the computer.
Installing the base cover
Prerequisites
If you are replacing a component, remove the existing component before performing the installation procedure.
About this task
The following image indicates the location of the base cover and provides a visual representation of the installation procedure.
Removing and installing components 21
Steps
1. Align and place the base cover on the computer, and snap the base cover latches into place.
2. Tighten the eight captive screws to secure the base cover to the computer.
Next steps
1. Install the microSD card.
2. Follow the procedure in after working inside your computer.
Solid-state drive
Removing the solid-state drive
Prerequisites
1. Follow the procedure in before working inside your computer.
2. Remove the microSD card.
3. Remove the base cover.
About this task
The following images indicate the location of the solid-state drive and provide a visual representation of the removal procedure.
22 Removing and installing components
Steps
1. Remove the screw (M2x2) that secures the SSD shield and remove the shield from the SSD.
2. Remove the screw (M2x2) that secures the SSD to the system board.
3. Slide and remove the solid-state drive from the M.2 slot on the system board.
NOTE: A thermal pad is included with the SSD plate and must always be adhered to the plate. If the thermal pad gets
separated from the plate or is adhered to the SSD, stick back the thermal pad to the SSD plate before reinstalling the
plate to the SSD.
Installing the solid-state drive
Prerequisites
If you are replacing a component, remove the existing component before performing the installation procedure.
About this task
The following image indicates the location of the solid-state drive and provides a visual representation of the installation
procedure.
Removing and installing components 23
Steps
1. Align the notch on the SSD with the tab on the M.2 slot and slide the SSD into the M.2 card slot on the system board.
2. Replace the screw (M2x2) that secures the SSD to the system board.
3. Replace the SSD shield, press to fit it firmly to cover the SSD, securing it with (M2x2) screw.
Next steps
1. Install the base cover.
2. Install the microSD card.
3. Follow the procedure in after working inside your computer.
WWAN card
Removing the WWAN card
Prerequisites
1. Follow the procedure in before working inside your computer.
2. Remove the microSD card.
3. Remove the base cover.
About this task
The following images indicate the location of the WWAN card and provide a visual representation of the removal procedure.
24 Removing and installing components
Steps
1. Using a plastic scribe, pry and remove the WWAN card shield covering the WWAN card.
NOTE: Pry open the WWAN card shield from the recess.
2. Loosen the single (M2x2.5) screw and remove the WWAN-card bracket.
3. Disconnect the antenna cables from the connectors on the WWAN card.
4. Slide and remove the WWAN card out from the M.2 slot on the system board.
Removing and installing components 25
Installing the WWAN card
Prerequisites
If you are replacing a component, remove the existing component before performing the installation procedure.
About this task
The following image indicates the location of the WWAN card and provides a visual representation of the installation procedure.
Steps
1. Align the notch on the WWAN card with the tab on the WWAN-card slot and slide the WWAN into the M.2 slot on the
system board.
2. Connect the antenna cables to the connectors on the WWAN card.
3. Align and place the WWAN-card bracket and tighten the single (M2x2.5) screw securing it to the system board.
4. Replace the WWAN-card shield over the WWAN card.
NOTE: Insert the edges of the WWAN-card shield into the clips on the system board to secure it in place.
26 Removing and installing components
NOTE: For instructions on how to find your computer's IMEI (International Mobile Station Equipment Identity) number,
see the knowledge base article 000143678 at https://www.dell.com/support/.
Next steps
1. Install the base cover.
2. Install the microSD card.
3. Follow the procedure in after working inside your computer.
Battery
Lithium-ion battery precautions
CAUTION:
●Exercise caution when handling Lithium-ion batteries.
●Discharge the battery completely before removing it. Disconnect the AC power adapter from the system and
operate the computer solely on battery power—the battery is fully discharged when the computer no longer
turns on when the power button is pressed.
●Do not crush, drop, mutilate, or penetrate the battery with foreign objects.
●Do not expose the battery to high temperatures, or disassemble battery packs and cells.
●Do not apply pressure to the surface of the battery.
●Do not bend the battery.
●Do not use tools of any kind to pry on or against the battery.
●Ensure any screws during the servicing of this product are not lost or misplaced, to prevent accidental
puncture or damage to the battery and other system components.
●If the battery gets stuck inside your computer as a result of swelling, do not try to release it as puncturing,
bending, or crushing a lithium-ion battery can be dangerous. In such an instance, contact Dell technical
support for assistance. See www.dell.com/contactdell.
●Always purchase genuine batteries from www.dell.com or authorized Dell partners and resellers.
●Swollen batteries should not be used and should be replaced and disposed properly. For guidelines on how to
handle and replace swollen Lithium-ion batteries, see Handling swollen Lithium-ion batteries.
Removing the 3-cell battery
Prerequisites
1. Follow the procedure in before working inside your computer.
2. Remove the microSD card.
3. Remove the base cover.
NOTE: If the battery is disconnected from system board, there is delay during computer boot as the computer undergoes
RTC (Real Time Clock) reset.
Removing and installing components 27
About this task
The following images indicate the location of the battery and provide a visual representation of the removal procedure.
Steps
1. Disconnect the battery cable from the system board.
2. Disconnect the speaker cable from the speaker board and release the speaker cable from the routing guides over the upper
right side of the battery.
3. Remove the single (M2.5x4) screw and loosen the four captive screws that secure the battery to the computer.
4. Lift and remove the battery from the computer.
Installing the 3-cell battery
Prerequisites
If you are replacing a component, remove the existing component before performing the installation procedure.
28 Removing and installing components
About this task
The following image indicates the location of the battery and provides a visual representation of the installation procedure.
NOTE: If the battery is disconnected from system board, there is delay during computer boot as the computer undergoes
RTC reset.
Steps
1. Align and place the battery into the computer.
2. Install the single (M2.5x4) screw and tighten the four captive screws to secure the battery in place.
3. Connect the speaker cable to the speaker board and reroute the speaker cable into its routing channel over the upper right
side of the battery
4. Connect the battery cable to the system board.
Next steps
1. Install the base cover.
2. Install the microSD card.
3. Follow the procedure in after working inside your computer.
Removing and installing components 29
Removing the 4-cell battery
Prerequisites
1. Follow the procedure in before working inside your computer.
2. Remove the microSD card.
3. Remove the base cover.
NOTE: If the battery is disconnected from system board, there is delay during computer boot as the computer undergoes
RTC reset.
About this task
The following images indicate the location of the battery and provide a visual representation of the removal procedure.
Steps
1. Disconnect the battery cable from the system board.
2. Disconnect the speaker cable from the speaker board and unroute the speaker cable from its routing channel over the upper
right side of the battery.
3. Remove the single (M2x4) screw and loosen the four captive screws that secure the battery to the computer.
30 Removing and installing components
4. Lift the battery and remove the battery from the computer.
Installing the 4-cell battery
Prerequisites
If you are replacing a component, remove the existing component before performing the installation procedure.
About this task
The following image indicates the location of the battery and provides a visual representation of the installation procedure.
NOTE: If the battery is disconnected from system board, there is delay during computer boot as the computer undergoes
RTC reset.
Steps
1. Align and place the battery into the computer.
2. Install the single (M2x4) screw and tighten the four captive screws to secure the battery in place.
Removing and installing components 31
3. Connect the speaker cable to the speaker board and reroute the speaker cable into its routing channel over the upper right
side of the battery.
4. Connect the battery cable to the system board.
Next steps
1. Install the base cover.
2. Install the microSD card.
3. Follow the procedure in after working inside your computer.
Heatsink assembly
Removing the heatsink assembly
Prerequisites
1. Follow the procedure in before working inside your computer.
2. Remove the microSD card.
3. Remove the base cover.
About this task
The following images indicate the location of the heatsink assembly and provide a visual representation of the removal
procedure.
Steps
1. Disconnect the fan cable from the system board.
2. Remove the two (M2x2.5) screws on the fan case and the four (M2x2.5) screws (in reverse order, 4->3->2->1) that secure
the heatsink to the computer.
3. Lift the heatsink assembly from the computer.
32 Removing and installing components
Installing the heatsink assembly
Prerequisites
If you are replacing a component, remove the existing component before performing the installation procedure.
About this task
The following image indicates the location of the heatsink assembly and provides a visual representation of the installation
procedure.
Steps
1. Align and place the heatsink assembly into its slot in the computer.
2. Replace the two (M2x2.5) screws on the fan casing and four (M2x2.5) screws (in sequential order, 1->2->3->4) to secure
the heatsink assembly to the computer.
3. Connect the fan cable to the system board.
Next steps
1. Install the base cover.
2. Install the microSD card.
3. Follow the procedure in after working inside your computer.
Palmrest antenna module
Removing the palmrest antenna module
Prerequisites
1. Follow the procedure in before working inside your computer.
2. Remove the microSD card.
Removing and installing components 33
3. Remove the base cover.
About this task
The following images indicate the location of the palmrest antenna module and provide a visual representation of the removal
procedure.
Steps
1. Remove the (M2x2) screw that secures the WLAN bracket to the system board.
2. Disconnect and unroute the antenna cables connected to the WLAN module on the system board.
3. Remove the two (M2x2.5) screws that secure the palmrest antenna module to the system.
4. Lift the palmrest antenna module away from the system.
Installing the palmrest antenna module
Prerequisites
If you are replacing a component, remove the existing component before performing the installation procedure.
About this task
The following image indicates the location of the palmrest antenna module and provides a visual representation of the
installation procedure.
34 Removing and installing components
Steps
1. Place the palmrest antenna module on the system and replace the two (M2x2.5) screws that secure it to the system.
2. Reroute the antenna cables through the routing channel and connect them to the WLAN module on the system board.
3. Replace the (M2x2) screw that secures the WLAN bracket to the system board.
Next steps
1. Install the base cover.
2. Install the microSD card.
3. Follow the procedure in after working inside your computer.
Display assembly
Removing the display assembly
Prerequisites
1. Follow the procedure in before working inside your computer.
2. Remove the microSD card.
3. Remove the base cover.
4. Remove the WWAN card.
About this task
The following images indicate the location of the display assembly and provide a visual representation of the removal procedure.
Removing and installing components 35
36 Removing and installing components
Steps
1. Remove the single (M2x2) securing the WLAN card bracket to the system board.
2. Lift the bracket from the WLAN card module on the system board.
3. Disconnect the WLAN antenna cables from the WLAN module.
4. Disconnect the WWAN antenna cable and release the cable from the rubber guides on the system board.
5. Remove the two (M2x2) securing the display cable bracket to the system board.
6. Lift to remove the display cable bracket from the computer.
7. Disconnect the display, camera, touch screen, sensor board cables from the system board and release them from cable
guiding tabs.
8. Open the display lid to 90º angle and remove the four (M2.5x5) screws securing the hinges to the palmrest assembly.
9. Remove the display assembly from the computer.
NOTE: NOTE: The display assembly is a Hinge-Up Design (HUD) assembly and cannot be further disassembled once it is
removed from the bottom chassis. If any components in the display assembly are malfunctioning and must be replaced,
replace the entire display assembly.
Removing and installing components 37
Figure 1. Display assembly with antennae cables
Installing the display assembly
Prerequisites
If you are replacing a component, remove the existing component before performing the installation procedure.
About this task
The following image indicates the location of the display assembly and provides a visual representation of the installation
procedure.
38 Removing and installing components
Removing and installing components 39
Steps
1. Align and place the display assembly at a 90º angle to the bottom chassis.
2. Replace the four (M2.5x5) screws securing the hinges to the bottom chassis.
3. Route the display cable along the guiding tabs and connect the display, camera, touch screen, sensor board cables to the
system board.
4. Connect the antenna cable to the WLAN module on the system board.
5. Replace the WLAN bracket on the antenna connector of the WLAN module on the system board.
6. Connect the WWAN antenna cables and route the antenna cables along the rubber guides on the system board.
7. Replace the single (M2x2) screw securing the WLAN card bracket to the system board.
8. Align and place the display cable bracket on the connector on the system board.
9. Install the two (M2x2) screws securing the display cable bracket to the system board.
Next steps
1. Install the WWAN card.
2. Install the base cover.
3. Install the microSD card.
4. Follow the procedure in after working inside your computer.
Audio board
Removing the audio board
Prerequisites
1. Follow the procedure in before working inside your computer.
2. Remove the microSD card.
3. Remove the base cover.
4. Remove the battery.
40 Removing and installing components
About this task
The following images indicate the location of the audio board and provide a visual representation of the removal procedure.
Steps
1. Disconnect the speaker cable from the system board.
2. Disconnect and peel the audio board FFC from the system board.
3. Remove the M2x2.5 screw that secures the audio board to the computer.
4. Lift and remove the audio board from the computer.
Installing the audio board
Prerequisites
If you are replacing a component, remove the existing component before performing the installation procedure.
About this task
The following image indicates the location of the audio board and provides a visual representation of the installation procedure.
Removing and installing components 41
Steps
1. Align and replace the audio board into its slot in the computer.
2. Replace the M2x2.5 screw to secure the audio board to the computer.
3. Connect the audio board FFC to the system board.
4. Connect the speaker cable to the system board.
Next steps
1. Install the battery.
2. Install the base cover.
3. Follow the procedure in after working inside your computer.
Speakers
Removing the speakers
Prerequisites
1. Follow the procedure in before working inside your computer.
2. Remove the microSD card.
3. Remove the base cover.
4. Remove the battery.
42 Removing and installing components
About this task
The following images indicate the location of the speakers and provide a visual representation of the removal procedure.
Steps
1. NOTE: The speaker cable is already disconnected from the system board.
Release the cable from the tabs on the palmrest assembly.
2. Lift and remove the speakers from the computer chassis.
Installing the speaker
Prerequisites
If you are replacing a component, remove the existing component before performing the installation procedure.
About this task
The following image indicates the location of the speaker and provides a visual representation of the installation procedure.
Removing and installing components 43
Steps
1. Replace the speaker into the slot in the computer.
2. Route the speaker cable along the cable guides on the palmrest assembly.
NOTE: While replacing the speakers, route the speaker cable into the routing channels along the bottom side of the
palmrest assembly.
Route the speaker cable underneath the LED board FFC.
Next steps
1. Install the battery.
2. Install the base cover.
3. Install the microSD card.
4. Follow the procedure in after working inside your computer.
SmartCard reader
Removing the smart card reader
Prerequisites
1. Follow the procedure in before working inside your computer.
44 Removing and installing components
Steps
1. Disconnect the touchpad module and peel the FFC cable from over the touchpad module.
2. Disconnect the smart card reader and NFC module cables from the USH board.
3. Remove the four (M2x2.5) screws and slide the smart card reader out from its slot in the chassis.
Installing the smart card reader
Prerequisites
If you are replacing a component, remove the existing component before performing the installation procedure.
About this task
The following image indicates the location of the smart card reader and provides a visual representation of the installation
procedure.
46 Removing and installing components
Steps
1. Slide the smart card reader into its slot in the computer chassis and secure it using the four (M2x2.5) screws.
2. Adhere the smart card reader and NFC module cable and connect it to the USH board.
3. Adhere the touchpad FFC cable along the sides of the touchpad module and connect it to the system board.
Next steps
1. Install the speaker.
2. Install the battery.
3. Install the base cover.
4. Install the microSD card.
5. Follow the procedure in after working inside your computer.
System board
Removing the system board
Prerequisites
1. Follow the procedure in before working inside your computer.
2. Remove the microSD card.
3. Remove the SIM card.
4. Remove the base cover.
5. Remove the solid-state drive.
6. Remove the battery.
7. Remove the WWAN card.
8. Remove the heatsink assembly.
Removing and installing components 47
CAUTION: Remove the heatsink assembly before removing the system board as there are two (M2x3) screws
underneath the heatsink that secures the system board to the computer.
NOTE: For configurations shipped with a carbon fiber palmrest and without WWAN antennas, the dummy SIM card tray
must removed from the system before removing the system board.
To remove the dummy SIM card tray, push the release latch inwards and then slide dummy card tray out of the computer.
NOTE: For non-WWAN configurations, remove the WWAN card shield and WWAN card bracket before removing the
system board.
About this task
The following images indicate the location of the system board and provide a visual representation of the removal procedure.
48 Removing and installing components
Steps
1. Remove the single (M2x2.5) screw from the finger print reader bracket and remove the bracket from the computer.
2. Disconnect the fingerprint reader FPC from the system board.
3. Remove the single (M2x2) screw and lift the bracket from the WLAN antenna cables.
4. Disconnect the WLAN antenna cables from the WLAN module on the system board.
5. Remove the single (M2x2) screw and lift the bracket from the WWAN card.
6. Disconnect the WWAN antenna cable and release the cable from the rubber guides on the system board.
7. Remove the two (M2x2) screws securing the display cable bracket to the system board.
8. Lift to remove the display cable bracket from the computer.
9. Disconnect the display, camera, touch screen, sensor board cables from the system board and unroute them from guiding
tabs.
10. Disconnect the speakers board FPC, audio board FFC, touchpad FFC, USH board FFC and, LED board FFC from the system
board.
11. Remove the single (M2x2.5) screw (For computer configuration with fingerprint reader on power button) or four (M2x2.5)
screws (For computer configuration without fingerprint reader), two (M2x4) screws, and two (M2x3) screws securing the
system board in place.
12. Carefully slide the system board out of the computer.
Installing the system board
Prerequisites
If you are replacing a component, remove the existing component before performing the installation procedure.
About this task
The following image indicates the location of the system board and provides a visual representation of the installation procedure.
Removing and installing components 49
50 Removing and installing components
Steps
1. Replace the system board into the computer chassis and tighten it using the single (M2x2.5) screw (for computer
configuration with fingerprint reader on power button) or four (M2x2.5) screws (for computer configuration without
fingerprint reader), two (M2x4) screws, and two (M2x3) screws securing the system board in place.
2. Connect the speakers board FPC, tweeter cable, audio board FFC, touchpad FFC, USH board FFC and, LED board FFC to
the system board.
3. Connect the display, camera, touch screen and, sensor board cables to the system board and route them along the guiding
tabs.
4. Replace the display cable bracket on the system board and secure it using the two (M2x2) screws.
5. Route the WWAN antenna cables along the rubber guides on the system board and connect it to the WWAN card.
6. Connect the WLAN antenna cables to the WLAN module on the system board.
7. Replace the WLAN antenna bracket and secure it to the system board using the single (M2x2) screw.
8. Connect the fingerprint reader FPC to the system board.
9. Replace the finger print reader bracket and secure to the system board using the single (M2x2.5) screw.
10. Place the WWAN antenna cable bracket and replace the M2x2.5 screw.
Next steps
1. Install the heatsink assembly.
2. Install the battery.
3. Install the WWAN card.
4. Install the solid-state drive.
5. Install the base cover.
6. Install the SIM card.
7. Install the microSD card.
8. Follow the procedure in after working inside your computer.
Removing and installing components 51
I/O board
Removing the I/O board
Prerequisites
1. Follow the procedure in before working inside your computer.
2. Remove the microSD card.
3. Remove the SIM card.
4. Remove the base cover.
5. Remove the solid-state drive.
6. Remove the WWAN card.
7. Remove the battery.
8. Remove the heatsink assembly.
9. Remove the system board.
About this task
The following images indicate the location of the I/O board and provide a visual representation of the removal procedure.
Steps
1. Remove the two (M2x4) screws that secure the I/O board to the computer.
2. Lift and remove the I/O board from the computer.
Installing the I/O board
Prerequisites
If you are replacing a component, remove the existing component before performing the installation procedure.
52 Removing and installing components
About this task
The following image indicates the location of the I/O board and provides a visual representation of the installation procedure.
Steps
1. Replace the I/O board into its slot in the computer.
2. Secure the I/O board to the computer using two (M2x4) screws.
Next steps
1. Install the system board.
2. Install the heatsink assembly.
3. Install the battery.
4. Install the WWAN card.
5. Install the solid-state drive.
6. Install the base cover.
7. Install the SIM card.
8. Install the microSD card.
9. Follow the procedure in after working inside your computer.
Power button with fingerprint reader
Removing the power button with fingerprint reader
Prerequisites
1. Follow the procedure in before working inside your computer.
2. Remove the microSD card.
3. Remove the SIM card.
4. Remove the base cover.
5. Remove the solid-state drive.
Removing and installing components 53
6. Remove the WWAN card.
7. Remove the battery.
8. Remove the heatsink assembly.
9. Remove the system board.
About this task
The following images indicate the location of the power button with fingerprint reader and provide a visual representation of the
removal procedure.
Steps
1. Remove the two (M1.6x1.7) screws securing the power button with fingerprint reader to the computer.
2. Lift and remove the power button with fingerprint reader from the computer.
Installing the power button with fingerprint reader
Prerequisites
If you are replacing a component, remove the existing component before performing the installation procedure.
About this task
The following image indicates the location of the power button with fingerprint reader and provides a visual representation of
the installation procedure.
54 Removing and installing components
Steps
1. Replace the power button with fingerprint reader into its slot in the computer.
2. Secure the power button with fingerprint reader to the computer using the two (M1.6x1.7) screws.
Next steps
1. Install the system board.
2. Install the heatsink assembly.
3. Install the battery.
4. Install the WWAN card.
5. Install the solid-state drive.
6. Install the base cover.
7. Install the SIM card.
8. Install the microSD card.
9. Follow the procedure in after working inside your computer.
Keyboard
Removing the keyboard
Prerequisites
1. Follow the procedure in before working inside your computer.
2. Remove the microSD card.
3. Remove the base cover.
4. Remove the solid-state drive.
5. Remove the WWAN card.
6. Remove the battery.
7. Remove the heatsink assembly.
8. Remove the audio board.
Removing and installing components 55
Steps
1. Peel the LED board FFC, USH board FFC, touchpad FFC and SmartCard reader FFC from the back of the keyboard.
2. Disconnect the keyboard FPC and keyboard backlight FPC from the touchpad module.
3. Remove the 26 (M1.6x1.7) screws that secure the keyboard assembly to the computer.
4. Carefully lift the keyboard assembly to remove it from the computer.
5. Remove the two (M2x2) screws securing the keyboard to the keyboard support plate.
6. Separate the keyboard from the keyboard support plate.
Installing the keyboard
Prerequisites
If you are replacing a component, remove the existing component before performing the installation procedure.
About this task
The following image indicates the location of the keyboard and provides a visual representation of the installation procedure.
Removing and installing components 57
58 Removing and installing components
Steps
1. Align and place the keyboard on the keyboard support plate and secure it using the two (M2x2) screw.
2. Replace the keyboard assembly in to its slot in the computer.
3. Connect the keyboard FPC and keyboard backlight FPC to the touchpad module.
4. Replace the 26 (M1.6x1.7) screws that secure the keyboard assembly to the computer.
5. Adhere the LED board FFC, USH board FFC , touchpad FFC and, SmartCard reader FFC to the back of the keyboard.
Next steps
1. Install the I/O board.
2. Install the system board.
3. Install the audio board.
4. Install the heatsink assembly.
5. Install the battery.
6. Install the WWAN card.
7. Install the solid-state drive.
8. Install the base cover.
9. Install the microSD card.
10. Follow the procedure in after working inside your computer.
Palmrest assembly
Removing the palmrest assembly
Prerequisites
1. Follow the procedure in before working inside your computer.
2. Remove the microSD card.
3. Remove the SIM card
4. Remove the base cover.
5. Remove the solid-state drive.
Removing and installing components 59
6. Remove the WWAN card.
7. Remove the battery.
8. Remove the heatsink assembly.
9. Remove the display assembly.
10. Remove the speaker.
11. Remove the smart card reader.
12. Remove the audio board.
13. Remove the system board.
14. Remove the I/O board.
15. Remove the power button with finger print reader.
16. Remove the keyboard.
Steps
After performing the pre-requisite steps, you are left with the palmrest assembly.
Installing the palmrest assembly
Prerequisites
If you are replacing a component, remove the existing component before performing the installation procedure.
About this task
The following image indicates the location of the palmrest assembly and provides a visual representation of the installation
procedure.
Steps
1. Place the palmrest assembly on a flat surface.
2. Transfer over the components to the new palmrest assembly.
Next steps
1. Install the keyboard.
2. Install the power button with finger print reader.
60 Removing and installing components
3. Install the I/O board.
4. Install the system board.
5. Install the audio board.
6. Install the smart card reader.
7. Install the speaker.
8. Install the display assembly.
9. Install the heatsink assembly.
10. Install the battery.
11. Install the WWAN card.
12. Install the solid-state drive.
13. Install the base cover.
14. Install the SIM card
15. Install the microSD card.
16. Follow the procedure in after working inside your computer.
Removing and installing components 61
Software
This chapter details the supported operating systems along with instructions on how to install the drivers.
Topics:
•Operating system
•Drivers and downloads
Operating system
Your Latitude 7420 supports the following operating systems:
●Windows 11 Home, 64-bit
●Windows 11 Pro, 64-bit
●Windows 11 Pro National Academic, 64-bit
●Windows 10 Home, 64-bit
●Windows 10 Pro, 64-bit
●Ubuntu 20.04 LTS, 64-bit
Drivers and downloads
When troubleshooting, downloading or installing drivers it is recommended that you read the Dell Knowledge Based article,
Drivers and Downloads FAQ 000123347.
3
62 Software
BIOS setup
CAUTION: Unless you are an expert computer user, do not change the settings in the BIOS Setup program.
Certain changes can make your computer work incorrectly.
NOTE: Depending on the computer and its installed devices, the items listed in this section may or may not be displayed.
NOTE: Before you change BIOS Setup program, it is recommended that you write down the BIOS Setup program screen
information for future reference.
Use the BIOS Setup program for the following purposes:
●Get information about the hardware installed in your computer, such as the amount of RAM and the size of the hard drive.
●Change the system configuration information.
●Set or change a user-selectable option, such as the user password, type of hard drive installed, and enabling or disabling
base devices.
Topics:
•BIOS overview
•Entering BIOS setup program
•Navigation keys
•One time boot menu
•System setup options
•Updating the BIOS
•System and setup password
•Clearing BIOS (System Setup) and System passwords
BIOS overview
The BIOS manages data flow between the computer's operating system and attached devices such as hard disk, video adapter,
keyboard, mouse, and printer.
Entering BIOS setup program
Steps
1. Turn on your computer.
2. Press F2 immediately to enter the BIOS setup program.
NOTE: If you wait too long and the operating system logo appears, continue to wait until you see the desktop. Then,
turn off your computer and try again.
Navigation keys
NOTE: For most of the System Setup options, changes that you make are recorded but do not take effect until you restart
the system.
4
BIOS setup 63
Table 2. Navigation keys
Keys Navigation
Up arrow Moves to the previous field.
Down arrow Moves to the next field.
Enter Selects a value in the selected field (if applicable) or follow
the link in the field.
Spacebar Expands or collapses a drop-down list, if applicable.
Tab Moves to the next focus area.
NOTE: For the standard graphics browser only.
Esc Moves to the previous page until you view the main screen.
Pressing Esc in the main screen displays a message that
prompts you to save any unsaved changes and restarts the
system.
One time boot menu
To enter one time boot menu, turn on your computer, and then press F12 immediately.
NOTE: It is recommended to shutdown the computer if it is on.
The one-time boot menu displays the devices that you can boot from including the diagnostic option. The boot menu options
are:
●Removable Drive (if available)
●STXXXX Drive (if available)
NOTE: XXX denotes the SATA drive number.
●Optical Drive (if available)
●SATA Hard Drive (if available)
●Diagnostics
The boot sequence screen also displays the option to access the System Setup screen.
System setup options
NOTE: Depending on your system and its installed devices, the items that are listed in this section may or may not appear.
Table 3. System setup options—System information menu
Overview
Latitude 7420
BIOS Version Displays the BIOS version number.
Service Tag Displays the Service Tag of the system.
Asset Tag Displays the Asset Tag of the system.
Manufacture Date Displays the manufacture date of the system.
Ownership Date Displays the ownership date of the system.
Express Service Code Displays the express service code of the system.
Ownership Tag Displays the Ownership Tag of the system.
Signed Firmware Update Displays whether the Signed Firmware Update is enabled on your system.
Battery Information
64 BIOS setup
Table 3. System setup options—System information menu (continued)
Overview
Primary Displays that battery is primary.
Battery Level Displays the battery level of the system.
Battery State Displays the battery state of the system.
Health Displays the battery health of the system.
AC Adapter Displays whether the AC adapter is connected or not.
Battery Type Displays the type of battery.
Processor Information
Processor Type Displays the processor type.
Maximum Clock Speed Displays the maximum processor clock speed.
Minimum Clock Speed Displays the minimum processor clock speed.
Current Clock Speed Displays the current processor clock speed.
Core Count Displays the number of cores on the processor.
Processor ID Displays the processor identification code.
Processor L2 Cache Displays the processor L2 Cache size.
Processor L3 Cache Displays the processor L3 Cache size.
Microcode Version Displays the microcode version.
Intel Hyper-Threading Capable Displays whether the processor is Hyper-Threading (HT) capable.
64-Bit Technology Displays whether 64-bit technology is used.
Memory Information
Memory Installed Displays the total system memory installed.
Memory Available Displays the total system memory available.
Memory Speed Displays the memory speed.
Memory Channel Mode Displays single or dual channel mode.
Memory Technology Displays the technology that is used for the memory.
Devices Information
Panel Type Displays the Panel Type of the system.
Privacy Screen Displays the Privacy Screen information of the system.
Video Controller Displays the video controller type of the system.
Video Memory Displays the video memory information of the system.
Wi-Fi Device Displays the wireless device information of the system.
Native Resolution Displays the native resolution of the system.
Video BIOS Version Displays the video BIOS version of the system.
Audio Controller Displays the audio controller information of the system.
Bluetooth Device Displays the Bluetooth device information of the system.
LOM MAC Address Displays the LAN On Motherboard (LOM) MAC address of the system.
Pass Through MAC Address Displays the pass through MAC address of the system.
Cellular Device Displays the M.2 PCIe SSD information of the system.
BIOS setup 65
Table 4. System setup options—Boot Configuration menu
Boot Configuration
Boot Sequence
Boot mode Displays the boot mode.
Boot Sequence Displays the boot sequence.
Secure Digital (SD) Card Boot Enable or disable the SD card read-only boot.
By default, the Secure Digital (SD) Card Boot option is not enabled.
Secure Boot
Enable Secure Boot Enable or disable the secure boot feature.
By default, the Secure Boot is enabled.
Secure Boot Mode Enable or disable to change the secure boot mode options.
By default, the option is not enabled.
Expert Key Management
Enable Custom Mode Enable or disable custom mode.
By default, the custom mode option is not enabled.
Custom Mode Key Management Select the custom values for expert key management.
Table 5. System setup options—Integrated Devices menu
Integrated Devices
Date/Time Displays the current date in MM/DD/YYYY format and current time in
HH:MM:SS AM/PM format.
Camera Enables or disable the camera.
By default, the Enable Camera option is selected
Audio
Enable Audio Enable or disable the integrated audio controller.
By default, all the options are enabled.
USB/Thunderbolt Configuration ●Enable or disable booting from USB mass storage devices that are
connected to external USB ports.
By default, the Enable External USB Ports option is enabled.
●Enable or disable booting from USB mass storage devices such as external
hard drive, optical drive, and USB drive.
By default, the Enable USB Boot Support option is enabled.
Enable Thunderbolt Technology
Support
Enable or disable the associated ports and adapters.
By default, the Enable Thunderbolt Technology Support option is selected.
Enable Thunderbolt Boot Support Enable or disable the Thunderbolt adapter peripheral device and USB devices
that are connected to the Thunderbolt adapter to be used during BIOS Pre-
boot.
By default, the Enable Thunderbolt Boot Support option is disabled.
Enable Thunderbolt (and PCIe behind
TBT) pre-boot modules
Enable or disable the PCIe devices that are connected through a Thunderbolt
adapter to execute the PCIe devices UEFI Option ROM (if present) during
pre-boot.
By default, the Enable Thunderbolt (and PCIe behind TBT) pre-boot
modules option is disabled.
66 BIOS setup
Table 5. System setup options—Integrated Devices menu (continued)
Integrated Devices
Disable USB4 PCIE Tunneling Disable the USB4 PCIE Tunneling option.
By default, the option is disabled.
Video/Power only on Type-C Ports Enable or disable the Type-C port functionality to video or only power.
By default, the Video/Power only on Type-C Ports option is disabled.
Type-C Dock Override Enables to use connected Type-C Dell Dock to provide data stream with
external USB ports disabled. When Type-C Dock override is enabled, the
Video/Audio/Lan submenu is activated.
By default, the Type-C Dock Override option is enabled.
Video Enable or disable the usage of video on Dell Dock external ports.
By default, the Video option is disabled.
Audio Enable or disable the usage of audio on Dell Dock external ports.
By default, the Audio option is enabled.
Lan Enable or disable the usage of LAN on Dell Dock external ports.
By default, the Lan option is enabled.
Miscellaneous Devices Enable or disable Fingerprint Reader device.
By default, the Enable Fingerprint Reader Device option is enabled.
Unobtrusive Mode
Enable Unobtrusive Mode Enable or disable all the system light and sound.
By default, the Enable Unobtrusive Mode option is disabled.
Table 6. System setup options—Storage menu
Storage
SATA/NVMe Operation
SATA/NVMe Operation Set the operating mode of the integrated storage device controller.
By default, the RAID On option is enabled.
Storage interface
Port Enablement This page allows you to enable the onboard drives.
By default, the M.2 PCIe SSD option is enabled.
SMART Reporting
Enable SMART Reporting Enable or disable Self-Monitoring, Analysis, and Reporting Technology
(SMART) during system startup.
By default, the Enable SMART Reporting option is not enabled.
Drive Information
M.2 PCIe SSD
Type Displays the M.2 PCIe SSD type information of the system.
Device Displays the M.2 PCIe SSD device information of the system.
Enable MediaCard
Secure Digital (SD) Card Enable or disable the SD card.
By default, the Secure Digital (SD) Card option is enabled.
Secure Digital (SD) Card Read-Only Mode Enable or disable the SD card read-only mode.
BIOS setup 67
Table 6. System setup options—Storage menu (continued)
Storage
By default, the Secure Digital (SD) Card Read-Only Mode option is not
enabled.
Table 7. System setup options—Display menu
Display
Display Brightness
Brightness on battery power Enable to set screen brightness when the system is running on battery power.
Brightness on AC power Enable to set screen brightness when the system is running on AC power.
Full Screen Logo Enable or disable full screen logo.
By default, the option is not enabled.
Table 8. System setup options—Connection menu
Connection
Wireless Device Enable
WWAN/GPS Enable or disable the internal WWAN/GPS device
By default, the option enabled.
WWAN Bus Mode Set the interface type of the Wireless Wan (WWAN) card.
By default, the Bus Mode PCIe option is enabled.
WLAN Enable or disable the internal WLAN device
By default, the option enabled.
Bluetooth Enable or disable the internal Bluetooth device
By default, the option enabled.
Contactless smartcard/NFC Enable or disable the internal Contactless smartcard/NFC device
By default, the option enabled.
Enable UEFI Network Stack Enable or disable UEFI Network Stack and controls the on-board LAN
Controller.
By default, the Enable UEFI Network Stack option is enabled.
Wireless Radio Control
Control WLAN radio Sense the connection of the system to a wired network and subsequently
disable the selected wireless radios (WLAN).
By default, the option is disabled.
Control WWAN radio Sense the connection of the system to a wired network and subsequently
disable the selected wireless radios (WWAN).
By default, the option is disabled.
HTTPs Boot Feature
HTTPs Boot Enable or disable the HTTPs Boot feature.
By default, the HTTPs Boot option is enabled.
HTTPs Boot Mode With Auto Mode, the HTTPs Boot extracts Boot URL from the DHCP. With
Manual Mode, the HTTPs Boot reads Boot URL from the user-provided data.
By default, the Auto Mode option is enabled.
68 BIOS setup
Table 9. System setup options—Power menu
Power
Battery configuration Enables the system to run on battery during peak power usage hours. Use the
table Custom Charge Start and Custom Charge Stop, to prevent AC power
usage between certain times of each day.
By default, the Adaptive option is enabled.
Advanced Configuration
Enable Advanced Battery Charge
Configuration
Enable or disable the advanced battery charge configuration.
By default, the Enable Advanced Battery Charge Configuration option is
disabled.
Peak Shift Enables the system to run on battery during peak power usage hours.
Enable Peak Shift By default, the Enable Peak Shift option is disabled.
USB PowerShare
Enable USB PowerShare Enable or disable the USB PowerShare.
By default, the Enable USB PowerShare option is disabled
Thermal Management Enables to cool the fan and processor heat management to adjust the system
performance, noise, and temperature.
By default, the Optimized option is enabled.
USB Wake Support
Wake on Dell USB-C Dock When enabled, connecting a Dell USB-C Dock will wake the system from
standby.
By default, the Wake on Dell USB-C Dock option is enabled.
Block Sleep Enables to block entering sleep (S3) mode in the operating system.
By default, the Block Sleep option is disabled.
Lid Switch Enable or disable the lid switch.
By default, the Lid Switch option is enabled.
Intel Speed Shift Technology Enable or disable the Intel speed shift technology support.
By default, the Intel Speed Shift Technology option is enabled.
Table 10. System setup options—Security menu
Security
TPM 2.0 Security
TPM 2.0 Security On Enable or disable TPM 2.0 security options.
By default, the TPM 2.0 Security On option is enabled.
Attestation Enable Enables to control whether the Trusted Platform Module (TPM) Endorsement
Hierarchy is available to the operating system.
By default, the Attestation Enable option is enabled.
Key Storage Enable Enables to control whether the Trusted Platform Module (TPM) Storage
Hierarchy is available to the operating system.
By default, the Key Storage Enable option is enabled.
SHA-256 BIOS and the TPM will use the SHA-256 hash algorithm to extend
measurements into the TPM PCRs during BIOS boot.
By default, the SHA-256 option is enabled.
BIOS setup 69
Table 10. System setup options—Security menu (continued)
Security
Clear Enables to clear the TPM owner information and returns the TPM to the
default state.
By default, the Clear option is disabled.
PPI ByPass for Clear Commands Controls the TPM Physical Presence Interface (PPI).
By default, the PPI ByPass for clear Commands option is disabled.
Intel Total Memory Encryption
Total Memory Encryption Enable or disable you to protect memory from physical attacks including freeze
spray, probing DDR to read the cycles, and others.
By default, the Total Memory Encryption option is disabled.
Chassis intrusion Controls the chassis intrusion feature.
By default, the On-Silent option is enabled.
Clear Intrusion Warning By default, the option is disabled.
SMM Security Mitigation Enable or disable SMM Security Mitigation.
By default, the option is enabled.
Data Wipe on Next Boot
Start Data Wipe Enable or disable the data wipe on next boot.
By default, the option is disabled.
Absolute Enable or disable or permanently disable the BIOS module interface of the
optional Absolute Persistence Module service from Absolute software.
By default, the option is enabled.
UEFI Boot Path Security Controls whether the system will prompt the user to enter the admin password
(if set) when booting to a UEFI boot device from the F12 boot menu.
By default, the Always Except Internal HDD option is enabled.
Table 11. System setup options—Passwords menu
Passwords
Admin Password Set, change, or delete the administrator password.
System Password Set, change, or delete the system password.
NVMe SSD0 Set, change, or delete the NVMe SSD0 password.
Password Configuration
Upper Case Letter Reinforces password must have at least one upper case letter.
By default, the option is enabled.
Lower Case Letter Reinforces password must have at least one lower case letter.
By default, the option is enabled.
Digit Reinforces password must have at least one digit.
By default, the option is enabled.
Special Character Reinforces password must have at least one special character.
By default, the option is enabled.
Minimum Characters Set the minimum characters allowed for password.
70 BIOS setup
Table 11. System setup options—Passwords menu (continued)
Passwords
Password Bypass When enabled, this always prompts for system and internal hard drive
passwords when powered on from the off state.
By default, the Disabled option is selected.
Password Changes
Enable Non-Admin Password Changes When On, user can change system and hard drive password without the need
for admin password.
By default, the option is On.
Admin Setup Lockout
Enable Admin Setup Lockout Enables administrators control over how their users can or cannot access BIOS
setup.
By default, the option is disabled.
Master Password Lockout
Enable Master Password Lockout When enabled, this disables the master password support.
By default, the option is disabled.
Allow Non-Admin PSID Revert
Enable Allow Non-Admin PSID Revert Controls access to the Physical Security ID (PSID) revert of NVMe hard-drives
from the Dell Security Manager prompt.
By default, the option is disabled.
Table 12. System setup options—Update, Recovery menu
Update, Recovery
UEFI Capsule Firmware Updates Enable or disable BIOS updates through UEFI capsule update packages.
By default, the option is enabled.
BIOS Recovery from Hard Drive Enables the user to recover from certain corrupted BIOS conditions from a
recovery file on the user primary hard drive or an external USB key.
By default, the option is enabled.
BIOS Downgrade
Allow BIOS Downgrade Enable or disable the flashing of the system firmware to previous revision is
blocked.
By default, the option is enabled.
SupportAssist OS Recovery Enable or disable the boot flow for SupportAssist OS Recovery tool in the
event of certain system errors.
By default, the option is enabled.
BIOSConnect Enable or disable cloud Service operating system recovery if the main operating
system fails to boot with the number of failures equal to or greater than the
value specified by the Auto operating system Recovery Threshold setup option
and local Service operating system does not boot or is not installed.
By default, the option is enabled.
Dell Auto operating system Recovery
Threshold
Controls the automatic boot flow for SupportAssist System Resolution Console
and for Dell operating system Recovery Tool.
By default, the threshold value is set to 2.
BIOS setup 71
Table 13. System setup options—System Management menu
System Management
Service Tag Display the Service Tag of the system.
Asset Tag Create a system Asset Tag.
AC Behavior
Wake on AC Enable or disable the wake on AC option.
By default, the option is disabled.
Wake on LAN
Wake on LAN Enable or disable the system to power on by special LAN signals when it
receives a wakeup signal from the WLAN.
By default, the Disabled option is selected.
Auto on Time Enable to set the system to turn on automatically every day or on a preselected
date and time. This option can be configured only if the Auto On Time is set to
Everyday, Weekdays, or Selected Days.
By default, the option is disabled.
Intel AMT Capability
Enable Intel AMT Capability By default Restrict MEBx Access option is enabled.
MEBx Hotkey
Enable MEBx Hotkey When enabled, this allows the use of Ctrl+P hotkey to access MEBx.
By default OFF option is disabled.
USB Provision
Enable USB Provision Intel AMT can be provisioned using the local provisioning file using a USB
storage device.
By default OFF option is disabled.
Table 14. System setup options—Keyboard menu
Keyboard
Fn Lock Options By default, the Fn lock option is enabled.
Keyboard Illumination Enables to change the keyboard illumination settings.
By default, the Disabled option is enabled.
Keyboard Backlight Timeout on AC Set the timeout value for the keyboard backlight when an AC adapter is
connected to the system.
By default, the 10 seconds option is enabled.
Keyboard Backlight Timeout on
Battery
Set the timeout value for the keyboard backlight when the is running only on
battery power.
By default, the 10 seconds option is enabled.
Device Configuration Hotkey Access Manages whether you can access device configuration screens through
hotkeys during system startup.
By default, the option is enabled.
Table 15. System setup options—Pre-boot Behavior menu
Pre-boot Behavior
Adapter Warnings
72 BIOS setup
Table 15. System setup options—Pre-boot Behavior menu (continued)
Pre-boot Behavior
Enable Adapter Warnings Enable or disable the warning messages during boot when the adapters with
less power capacity are detected.
By default, the option is enabled.
Warning and Errors Enable or disable the action to be done when a warning or error is encountered.
By default, the Prompt on Warnings and Errors option is enabled.
USB-C Warnings
Enable Dock Warning Messages By default, the option is enabled.
Fastboot Enable to set the speed of the boot process.
By default, the Minimal option is enabled.
Extend BIOS POST Time Set the BIOS POST time.
By default, the 0 seconds option is enabled.
MAC Address Pass-Through Replaces the external NIC MAC address with the selected MAC address from
the system.
By default, the System Unique MAC Address option is enabled.
Mouse/Touchpad By default, the Touchpad and PS/2 Mouse option is enabled.
Table 16. System setup options—Virtualization menu
Virtualization
Intel Virtualization Technology
Enable Intel Virtualization Technology
(VT)
Specify whether a Virtual Machine Monitor (VMM) can use the additional
hardware capabilities that are provided by Intel Virtualization Technology.
By default, the option is enabled.
VT for Direct I/O Specify whether a Virtual Machine Monitor (VMM) can use the additional
hardware capabilities that are provided by Intel Virtualization Technology for
Direct I/O.
By default, the option is enabled.
Intel Trusted Execution Technology
(TXT)
Enable Intel Trusted Execution
Technology (TXT)
Specifies whether a measured Virtual Machine Monitor (MVMM) can use the
additional hardware capabilities that are provided by Intel Trusted Execution
Technology.
By default, the option is disabled.
Table 17. System setup options—Performance menu
Performance
Multi Core Support
Active Cores Enables to change the number of CPU cores available to the operating system.
By default, the All Cores option is enabled.
Intel SpeedStep
Enable Intel SpeedStep Technology Enables the system to dynamically adjust processor voltage and core
frequency, decreasing average power consumption and heat production.
By default, the option is enabled.
BIOS setup 73
Table 17. System setup options—Performance menu (continued)
Performance
C-States Control
Enable C-State Control Enable or disable additional processor sleep states.
By default, the option is enabled.
Intel TurbocBoost Technology
Enable Intel Turbo Boost Technology Enable or disable Intel TurboBoost mode of the processor.
By default, the option is enabled.
Intel Hyper-Threading Technology
Enable Intel Hyper-Threading Technology Enable or disable Hyper-Threading in the processor.
By default, the option is enabled.
Dynamic Tuning:Machine Learning
Enable Dynamic Tuning:Machine Learning Enables the operating system capability to enhance dynamic power tuning
capabilities based on detected workloads.
By default, the option is disabled.
Table 18. System setup options—System Logs menu
System Logs
BIOS Event Log
Clear Bios Event Log Display BIOS events.
By default, the Keep option is enabled.
Thermal Event Log
Clear Thermal Event Log Display Thermal events.
By default, the Keep option is enabled.
Power Event Log
Clear Power Event Log Display power events.
By default, the Keep option is enabled.
License Information Displays the license information of the system.
Updating the BIOS
Updating the BIOS in Windows
About this task
CAUTION: If BitLocker is not suspended before updating the BIOS, the next time you reboot the system it
will not recognize the BitLocker key. You will then be prompted to enter the recovery key to progress and the
system will ask for this on each reboot. If the recovery key is not known this can result in data loss or an
unnecessary operating system re-install. For more information on this subject, see Knowledge Article: https://
www.dell.com/support/article/sln153694
Steps
1. Go to www.dell.com/support.
2. Click Product support. In the Search support box, enter the Service Tag of your computer, and then click Search.
74 BIOS setup
NOTE: If you do not have the Service Tag, use the SupportAssist feature to automatically identify your computer. You
can also use the product ID or manually browse for your computer model.
3. Click Drivers & Downloads. Expand Find drivers.
4. Select the operating system installed on your computer.
5. In the Category drop-down list, select BIOS.
6. Select the latest version of BIOS, and click Download to download the BIOS file for your computer.
7. After the download is complete, browse the folder where you saved the BIOS update file.
8. Double-click the BIOS update file icon and follow the on-screen instructions.
For more information, see knowledge base article 000124211 at www.dell.com/support.
Updating the BIOS in Linux and Ubuntu
To update the system BIOS on a computer that is installed with Linux or Ubuntu, see the knowledge base article 000131486 at
www.dell.com/support.
Updating the BIOS using the USB drive in Windows
About this task
CAUTION: If BitLocker is not suspended before updating the BIOS, the next time you reboot the system it
will not recognize the BitLocker key. You will then be prompted to enter the recovery key to progress and the
system will ask for this on each reboot. If the recovery key is not known this can result in data loss or an
unnecessary operating system re-install. For more information on this subject, see Knowledge Article: https://
www.dell.com/support/article/sln153694
Steps
1. Follow the procedure from step 1 to step 6 in Updating the BIOS in Windows to download the latest BIOS setup program file.
2. Create a bootable USB drive. For more information, see the knowledge base article 000145519 at www.dell.com/support.
3. Copy the BIOS setup program file to the bootable USB drive.
4. Connect the bootable USB drive to the computer that needs the BIOS update.
5. Restart the computer and press F12 .
6. Select the USB drive from the One Time Boot Menu.
7. Type the BIOS setup program filename and press Enter.
The BIOS Update Utility appears.
8. Follow the on-screen instructions to complete the BIOS update.
Updating the BIOS from the F12 One-Time boot menu
Update your computer BIOS using the BIOS update.exe file that is copied to a FAT32 USB drive and booting from the F12
One-Time boot menu.
About this task
CAUTION: If BitLocker is not suspended before updating the BIOS, the next time you reboot the system it
will not recognize the BitLocker key. You will then be prompted to enter the recovery key to progress and the
system will ask for this on each reboot. If the recovery key is not known this can result in data loss or an
unnecessary operating system re-install. For more information on this subject, see Knowledge Article: https://
www.dell.com/support/article/sln153694
BIOS Update
You can run the BIOS update file from Windows using a bootable USB drive or you can also update the BIOS from the F12
One-Time boot menu on the computer.
BIOS setup 75
Most of the Dell computers built after 2012 have this capability, and you can confirm by booting your computer to the F12
One-Time Boot Menu to see if BIOS FLASH UPDATE is listed as a boot option for your computer. If the option is listed, then the
BIOS supports this BIOS update option.
NOTE: Only computers with BIOS Flash Update option in the F12 One-Time boot menu can use this function.
Updating from the One-Time boot menu
To update your BIOS from the F12 One-Time boot menu, you need the following:
●USB drive formatted to the FAT32 file system (key does not have to be bootable)
●BIOS executable file that you downloaded from the Dell Support website and copied to the root of the USB drive
●AC power adapter that is connected to the computer
●Functional computer battery to flash the BIOS
Perform the following steps to perform the BIOS update flash process from the F12 menu:
CAUTION: Do not turn off the computer during the BIOS update process. The computer may not boot if you turn
off your computer.
Steps
1. From a turn off state, insert the USB drive where you copied the flash into a USB port of the computer.
2. Turn on the computer and press F12 to access the One-Time Boot Menu, select BIOS Update using the mouse or arrow keys
then press Enter.
The flash BIOS menu is displayed.
3. Click Flash from file.
4. Select external USB device.
5. Select the file and double-click the flash target file, and then click Submit.
6. Click Update BIOS. The computer restarts to flash the BIOS.
7. The computer will restart after the BIOS update is completed.
System and setup password
Table 19. System and setup password
Password type Description
System password Password that you must enter to log in to your system.
Setup password Password that you must enter to access and make changes to
the BIOS settings of your computer.
You can create a system password and a setup password to secure your computer.
CAUTION: The password features provide a basic level of security for the data on your computer.
CAUTION: Anyone can access the data that is stored on your computer if it is not locked and left unattended.
NOTE: System and setup password feature is disabled.
Assigning a system setup password
Prerequisites
You can assign a new System or Admin Password only when the status is in Not Set.
About this task
To enter the system setup, press F12 immediately after a power-on or reboot.
76 BIOS setup
Steps
1. In the System BIOS or System Setup screen, select Security and press Enter.
The Security screen is displayed.
2. Select System/Admin Password and create a password in the Enter the new password field.
Use the following guidelines to assign the system password:
●At least one special character: ! " # $ % & ' ( ) * + , - . / : ; < = > ? @ [ \ ] ^ _ ` { | }
●Numbers 0 through 9.
●Upper case letters from A to Z.
●Lower case letters from a to z.
3. Type the system password that you entered earlier in the Confirm new password field and click OK.
4. Press Esc and save the changes as prompted by the pop-up message.
5. Press Y to save the changes.
The computer restarts.
Deleting or changing an existing system setup password
Prerequisites
Ensure that the Password Status is Unlocked (in the System Setup) before attempting to delete or change the existing
System and/or Setup password. You cannot delete or change an existing System or Setup password, if the Password Status is
Locked.
About this task
To enter the System Setup, press F12 immediately after a power-on or reboot.
Steps
1. In the System BIOS or System Setup screen, select System Security and press Enter.
The System Security screen is displayed.
2. In the System Security screen, verify that Password Status is Unlocked.
3. Select System Password, update, or delete the existing system password, and press Enter or Tab.
4. Select Setup Password, update, or delete the existing setup password, and press Enter or Tab.
NOTE: If you change the System and/or Setup password, reenter the new password when prompted. If you delete the
System and/or Setup password, confirm the deletion when prompted.
5. Press Esc and a message prompts you to save the changes.
6. Press Y to save the changes and exit from System Setup.
The computer restarts.
Clearing BIOS (System Setup) and System passwords
About this task
To clear the system or BIOS passwords, contact Dell technical support as described at www.dell.com/contactdell.
NOTE: For information on how to reset Windows or application passwords, refer to the documentation accompanying
Windows or your application.
BIOS setup 77
Troubleshooting
Topics:
•Handling swollen Lithium-ion batteries
•Dell SupportAssist Pre-boot System Performance Check diagnostics
•Built-in self-test (BIST)
•System-diagnostic lights
•Recovering the operating system
•Real-Time Clock (RTC Reset)
•Backup media and recovery options
•WiFi power cycle
•Drain residual flea power (perform hard reset)
Handling swollen Lithium-ion batteries
Like most laptops, Dell laptops use lithium-ion batteries. One type of lithium-ion battery is the lithium-ion polymer battery.
Lithium-ion polymer batteries have increased in popularity in recent years and have become standard in the electronics industry
due to customer preferences for a slim form factor (especially with newer ultra-thin laptops) and long battery life. Inherent to
lithium-ion polymer battery technology is the potential for swelling of the battery cells.
Swollen battery may impact the performance of the laptop. To prevent possible further damage to the device enclosure or
internal components leading to malfunction, discontinue the use of the laptop and discharge it by disconnecting the AC adapter
and letting the battery drain.
Swollen batteries should not be used and should be replaced and disposed of properly. We recommend contacting Dell product
support for options to replace a swollen battery under the terms of the applicable warranty or service contract, including options
for replacement by a Dell authorized service technician.
The guidelines for handling and replacing Lithium-ion batteries are as follows:
●Exercise caution when handling Lithium-ion batteries.
●Discharge the battery before removing it from the system. To discharge the battery, unplug the AC adapter from the system
and operate the system only on battery power. When the system will no longer power on when the power button is pressed,
the battery is fully discharged.
●Do not crush, drop, mutilate, or penetrate the battery with foreign objects.
●Do not expose the battery to high temperatures, or disassemble battery packs and cells.
●Do not apply pressure to the surface of the battery.
●Do not bend the battery.
●Do not use tools of any type to pry on or against the battery.
●If a battery gets stuck in a device as a result of swelling, do not try to free it as puncturing, bending, or crushing a battery
can be dangerous.
●Do not attempt to reassemble a damaged or swollen battery into a laptop.
●Swollen batteries that are covered under warranty should be returned to Dell in an approved shipping container (provided
by Dell)—this is to comply with transportation regulations. Swollen batteries that are not covered under warranty should be
disposed of at an approved recycling center. Contact Dell product support at https://www.dell.com/support for assistance
and further instructions.
●Using a non-Dell or incompatible battery may increase the risk of fire or explosion. Replace the battery only with a
compatible battery purchased from Dell that is designed to work with your Dell computer. Do not use a battery from other
computers with your computer. Always purchase genuine batteries from https://www.dell.com or otherwise directly from
Dell.
Lithium-ion batteries can swell for various reasons such as age, number of charge cycles, or exposure to high heat. For more
information on how to improve the performance and lifespan of the laptop battery and to minimize the possibility of occurrence
of the issue, see Dell Laptop Battery - Frequently Asked Questions.
5
78 Troubleshooting
Dell SupportAssist Pre-boot System Performance
Check diagnostics
About this task
SupportAssist diagnostics (also known as system diagnostics) performs a complete check of your hardware. The Dell
SupportAssist Pre-boot System Performance Check diagnostics is embedded with the BIOS and is launched by the BIOS
internally. The embedded system diagnostics provides a set of options for particular devices or device groups allowing you to:
●Run tests automatically or in an interactive mode
●Repeat tests
●Display or save test results
●Run thorough tests to introduce additional test options to provide extra information about the failed device(s)
●View status messages that inform you if tests are completed successfully
●View error messages that inform you of problems encountered during testing
NOTE: Some tests for specific devices require user interaction. Always ensure that you are present at the computer
terminal when the diagnostic tests are performed.
For more information, see https://www.dell.com/support/kbdoc/000180971.
Running the SupportAssist Pre-Boot System Performance Check
Steps
1. Turn on your computer.
2. As the computer boots, press the F12 key as the Dell logo appears.
3. On the boot menu screen, select the Diagnostics option.
4. Click the arrow at the bottom left corner.
Diagnostics front page is displayed.
5. Click the arrow in the lower-right corner to go to the page listing.
The items detected are listed.
6. To run a diagnostic test on a specific device, press Esc and click Yes to stop the diagnostic test.
7. Select the device from the left pane and click Run Tests.
8. If there are any issues, error codes are displayed.
Note the error code and validation number and contact Dell.
Built-in self-test (BIST)
M-BIST
M-BIST (Built In Self-Test) is the system board's built-in self-test diagnostics tool that improves the diagnostics accuracy of
system board embedded controller (EC) failures.
NOTE: M-BIST can be manually initiated before POST (Power On Self Test).
How to run M-BIST
NOTE: M-BIST must be initiated on the system from a power-off state either connected to AC power or with battery only.
1. Press and hold both the M key on the keyboard and the power button to initiate M-BIST.
2. With both the M key and the power button held down, the battery indicator LED may exhibit two states:
a. OFF: No fault detected with the system board
b. AMBER: Indicates a problem with the system board
3. If there is a failure with the system board, the battery status LED will flash one of the following error codes for 30 seconds:
Troubleshooting 79
Table 20. LED error codes
Blinking Pattern Possible Problem
Amber White
2 1 CPU Failure
2 8 LCD Power Rail Failure
1 1 TPM Detection Failure
2 4 Unrecoverable SPI Failure
4. If there is no failure with the system board, the LCD will cycle through the solid color screens described in the LCD-BIST
section for 30 seconds and then power off.
LCD Power rail test (L-BIST)
L-BIST is an enhancement to the single LED error code diagnostics and is automatically initiated during POST. L-BIST will check
the LCD power rail. If there is no power being supplied to the LCD (i.e., the L-BIST circuit fails), the battery status LED will flash
either an error code [2,8] or an error code [2,7].
NOTE: If L-BIST fails, LCD-BIST cannot function as no power will be supplied to the LCD.
How to invoke L-BIST Test:
1. Press the power button to start the system.
2. If the system does not start up normally, look at the battery status LED:
●If the battery status LED flashes an error code [2,7], the display cable may not be connected properly.
●If the battery status LED flashes an error code [2,8], there is a failure on the LCD power rail of the system board, hence
there is no power supplied to the LCD.
3. For cases, when a [2,7] error code is shown, check to see if the display cable is properly connected.
4. For cases when a [2,8] error code is shown, replace the system board.
LCD Built-in Self Test (BIST)
Dell laptops have a built-in diagnostic tool that helps you determine if the screen abnormality you are experiencing is an inherent
problem with the LCD (screen) of the Dell laptop or with the video card (GPU) and PC settings.
When you notice screen abnormalities like flickering, distortion, clarity issues, fuzzy or blurry image, horizontal or vertical lines,
color fade etc., it is always a good practice to isolate the LCD (screen) by running the Built-In Self Test (BIST).
How to invoke LCD BIST Test
1. Power off the Dell laptop.
2. Disconnect any peripherals that are connected to the laptop. Connect only the AC adapter (charger) to the laptop.
3. Ensure that the LCD (screen) is clean (no dust particles on the surface of the screen).
4. Press and hold D key and Power on the laptop to enter LCD built-in self test (BIST) mode. Continue to hold the D key, until
the system boots up.
5. The screen will display solid colors and change colors on the entire screen to white, black, red, green, and blue twice.
6. Then it will display the colors white, black and red.
7. Carefully inspect the screen for abnormalities (any lines, fuzzy color or distortion on the screen).
8. At the end of the last solid color (red), the system will shut down.
NOTE: Dell SupportAssist Pre-boot diagnostics upon launch, initiates an LCD BIST first, expecting a user intervention
confirm functionality of the LCD.
80 Troubleshooting
System-diagnostic lights
Table 21. System-diagnostic lights
Blinking pattern
Problem description Suggested resolutionAmber White
1 1 TPM detection failure Replace the system board.
1 2 Unrecoverable SPI Flash
Failure Replace the system board.
1 5 EC unable to program i-Fuse Replace the system board.
1 6 Generic catch-all for
ungraceful EC code flow
errors
Disconnect all power source
(AC, battery, coin cell) and
drain flea power by pressing
and holding down power
button for 3~5 seconds.
2 1 CPU failure ●Run the Dell Support
Assist/Dell Diagnostics
tool.
●If problem persists,
replace the system board.
2 2 System board failure (included
BIOS corruption or ROM
error)
●Flash latest BIOS version
●If problem persists,
replace the system board.
2 3 No memory/RAM detected ●Confirm that the memory
module is installed
properly.
●If problem persists,
replace the memory
module.
2 4 Memory/RAM failure ●Reset and swap memory
modules among the slots.
●If problem persists,
replace the memory
module.
2 5 Invalid memory installed ●Reset and swap memory
modules among the slots.
●If problem persists,
replace the memory
module.
2 6 System board/Chipset Error Replace the system board.
2 7 LCD failure (SBIOS message) Replace the LCD module.
2 8 LCD failure (EC detection of
power rail failure) Replace the system board.
3 1 CMOS battery failure ●Reset the main battery
connection.
●If problem persists,
replace the main battery.
3 2 PCI or Video card/chip failure Replace the system board.
3 3 BIOS Recovery image not
found
●Flash latest BIOS version
Troubleshooting 81
Table 21. System-diagnostic lights (continued)
Blinking pattern
Problem description Suggested resolutionAmber White
●If problem persists,
replace the system board.
3 4 BIOS Recovery image found
but invalid
●Flash latest BIOS version
●If problem persists,
replace the system board.
3 5 Power rail failure Replace the system board.
3 6 Flash corruption detected by
SBIOS.
●Press power button for
over 25 seconds to do
RTC reset. If problem
persists, replace the
system board.
●Disconnect all power
source (AC, battery, coin
cell) and drain flea power
by pressing and holding
down power button 3~5
seconds to ensure all
power are drained.
●Run "BIOS recovery from
USB", and the instructions
are in the website Dell
support.
●If problem persists,
replace the system board.
3 7 Timeout waiting on ME to
reply to HECI message. Replace the system board.
NOTE: Blinking 3-3-3 LEDs on Lock LED (Caps-Lock or Nums-Lock), Power button LED (without Fingerprint reader), and
Diagnostic LED indicates failure to provide input during LCD panel test on Dell SupportAssist Pre-boot System Performance
Check diagnostics.
Recovering the operating system
When your computer is unable to boot to the operating system even after repeated attempts, it automatically starts Dell
SupportAssist OS Recovery.
Dell SupportAssist OS Recovery is a standalone tool that is preinstalled in all Dell computers installed with Windows operating
system. It consists of tools to diagnose and troubleshoot issues that may occur before your computer boots to the operating
system. It enables you to diagnose hardware issues, repair your computer, back up your files, or restore your computer to its
factory state.
You can also download it from the Dell Support website to troubleshoot and fix your computer when it fails to boot into their
primary operating system due to software or hardware failures.
For more information about the Dell SupportAssist OS Recovery, see Dell SupportAssist OS Recovery User's Guide at
www.dell.com/serviceabilitytools. Click SupportAssist and then, click SupportAssist OS Recovery.
Real-Time Clock (RTC Reset)
The Real Time Clock (RTC) reset function allows you to recover Dell computer from No POST, No Power or, No Boot like
situations. There is no coin-cell battery on this computer, the main battery reserves 2% of its capacity for RTC function.
How to Reset the Real-Time Clock (RTC)
82 Troubleshooting
●Start the RTC reset with the computer powered off and connected to AC power.
●Press and hold the power button for thirty (30-35) seconds.
●The computer RTC Reset occurs after you release the power button.
NOTE: For more information, see the knowledge base article 000125880 at https://www.dell.com/support/.
Backup media and recovery options
It is recommended to create a recovery drive to troubleshoot and fix problems that may occur with Windows. Dell proposes
multiple options for recovering Windows operating system on your Dell PC. For more information. see Dell Windows Backup
Media and Recovery Options.
WiFi power cycle
About this task
If your computer is unable to access the internet due to WiFi connectivity issues a WiFi power cycle procedure may be
performed. The following procedure provides the instructions on how to conduct a WiFi power cycle:
NOTE: Some ISPs (Internet Service Providers) provide a modem/router combo device.
Steps
1. Turn off your computer.
2. Turn off the modem.
3. Turn off the wireless router.
4. Wait for 30 seconds.
5. Turn on the wireless router.
6. Turn on the modem.
7. Turn on your computer.
Drain residual flea power (perform hard reset)
About this task
Flea power is the residual static electricity that remains in the computer even after it has been powered off and the battery is
removed.
For your safety, and to protect the sensitive electronic components in your computer, you are requested to drain residual flea
power before removing or replacing any components in your computer.
Draining residual flea power, also known as a performing a "hard reset", is also a common troubleshooting step if your computer
does not power on or boot into the operating system.
To drain residual flea power (perform a hard reset)
Steps
1. Turn off your computer.
2. Disconnect the power adapter from your computer.
3. Remove the base cover.
4. Remove the battery.
5. Press and hold the power button for 20 seconds to drain the flea power.
6. Install the battery.
7. Install the base cover.
8. Connect the power adapter to your computer.
9. Turn on your computer.
Troubleshooting 83
Getting help and contacting Dell
Self-help resources
You can get information and help on Dell products and services using these self-help resources:
Table 22. Self-help resources
Self-help resources Resource location
Information about Dell products and services www.dell.com
My Dell app
Tips
Contact Support In Windows search, type Contact Support, and press
Enter.
Online help for operating system www.dell.com/support/windows
Access top solutions, diagnostics, drivers and downloads, and
learn more about your computer through videos, manuals and
documents.
Your Dell computer is uniquely identified by a Service Tag or
Express Service Code. To view relevant support resources for
your Dell computer, enter the Service Tag or Express Service
Code at www.dell.com/support.
For more information on how to find the Service Tag for your
computer, see Locate the Service Tag on your computer.
Dell knowledge base articles for a variety of computer
concerns 1. Go to www.dell.com/support.
2. On the menu bar at the top of the Support page, select
Support > Knowledge Base.
3. In the Search field on the Knowledge Base page, type the
keyword, topic, or model number, and then click or tap the
search icon to view the related articles.
Contacting Dell
To contact Dell for sales, technical support, or customer service issues, see www.dell.com/contactdell.
NOTE: Availability varies by country/region and product, and some services may not be available in your country/region.
NOTE: If you do not have an active Internet connection, you can find contact information about your purchase invoice,
packing slip, bill, or Dell product catalog.
6
Getting help and contacting Dell 85