Dell Latitude 7220EX User manual

Latitude 7220EX Rugged Extreme Tablet
Service Manual
Regulatory Model: T03H
Regulatory Type: T03H004
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.
© 2019 - 2020 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 tablet................................................................................................. 5
Safety instructions.............................................................................................................................................................. 5
Before working inside the tablet................................................................................................................................ 5
Safety precautions........................................................................................................................................................ 6
Electrostatic discharge—ESD protection............................................................................................................... 6
ESD field service kit ..................................................................................................................................................... 7
After working inside the tablet................................................................................................................................... 8
Chapter 2: Major components of the tablet................................................................................... 9
Chapter 3: Field service information.............................................................................................11
Safety instructions............................................................................................................................................................. 11
Before working inside the tablet.............................................................................................................................. 12
Safety precautions.......................................................................................................................................................12
Electrostatic discharge—ESD protection.............................................................................................................. 12
User warning guide...................................................................................................................................................... 13
ESD field service kit ....................................................................................................................................................13
After working inside the tablet................................................................................................................................. 14
Recommended tools..........................................................................................................................................................14
Screw list............................................................................................................................................................................. 15
Customer Replaceable Units (CRU) and Field Replaceable Units (FRU) list...................................................... 16
Disassembly and reassembly .......................................................................................................................................... 17
Batteries cover assembly........................................................................................................................................... 18
System cover................................................................................................................................................................ 21
Batteries........................................................................................................................................................................ 24
Subscriber Identification Module (SIM) card........................................................................................................27
Stylus..............................................................................................................................................................................28
Display assembly..........................................................................................................................................................30
SSD Heat sink...............................................................................................................................................................38
System fan.................................................................................................................................................................... 40
Solid-state drive...........................................................................................................................................................42
WLAN card....................................................................................................................................................................44
WWAN card.................................................................................................................................................................. 47
Microphone................................................................................................................................................................... 49
Front camera.................................................................................................................................................................51
Coin-cell battery.......................................................................................................................................................... 55
System board............................................................................................................................................................... 58
Rear Camera................................................................................................................................................................. 64
Micro serial port and power connector port.........................................................................................................66
Chapter 4: System setup.............................................................................................................69
Boot menu...........................................................................................................................................................................69
Navigation keys..................................................................................................................................................................69
Boot Sequence...................................................................................................................................................................70
Contents
Contents 3

System setup options.......................................................................................................................................................70
General options............................................................................................................................................................ 70
System information......................................................................................................................................................71
Video............................................................................................................................................................................... 73
Security.......................................................................................................................................................................... 73
Secure boot...................................................................................................................................................................74
Intel Software Guard Extensions............................................................................................................................. 75
Performance................................................................................................................................................................. 75
Power management.................................................................................................................................................... 76
POST behavior............................................................................................................................................................. 77
Manageability................................................................................................................................................................78
Virtualization support..................................................................................................................................................78
Wireless..........................................................................................................................................................................79
Maintenance screen....................................................................................................................................................79
System logs...................................................................................................................................................................80
SupportAssist System Resolution........................................................................................................................... 80
About.............................................................................................................................................................................. 80
Updating the BIOS in Windows .................................................................................................................................... 80
Updating BIOS on systems with BitLocker enabled............................................................................................ 81
Updating your system BIOS using a USB flash drive.......................................................................................... 81
Flashing the BIOS from the F12 One-Time boot menu...................................................................................... 82
System and setup password...........................................................................................................................................85
Assigning a system setup password....................................................................................................................... 85
Deleting or changing an existing system setup password.................................................................................86
Chapter 5: Software.................................................................................................................... 87
Drivers and downloads..................................................................................................................................................... 87
Chapter 6: Troubleshooting.........................................................................................................88
Handling swollen Lithium-ion batteries........................................................................................................................ 88
Enhanced Pre-Boot System Assessment (ePSA) diagnostics...............................................................................89
Running the ePSA diagnostics................................................................................................................................. 89
Built-in self-test (BIST)................................................................................................................................................... 89
M-BIST...........................................................................................................................................................................89
LCD Power rail test (L-BIST)................................................................................................................................... 90
LCD Built-in Self Test (BIST)................................................................................................................................... 90
System diagnostic lights...................................................................................................................................................91
Backup media and recovery options..............................................................................................................................91
Recovering the operating system................................................................................................................................. 92
WiFi power cycle............................................................................................................................................................... 92
Drain residual flea power (perform hard reset)......................................................................................................... 92
Chapter 7: Getting help and contacting Dell................................................................................ 94
4Contents

Working on your tablet
Topics:
•Safety instructions
Safety instructions
Prerequisites
Use the following safety guidelines to protect your tablet from potential damage and to ensure your personal safety. Unless
otherwise noted, each procedure in this document assumes that the following conditions exist:
●You have read the safety information that shipped with your tablet.
●A component can be replaced or, if purchased separately, installed by performing the removal procedure in reverse order.
About this task
NOTE: Disconnect all power sources before opening the tablet. After you finish working inside your tablet, replace all the
components and screws before connection the power source.
WARNING: Before working inside your tablet, read the safety information that shipped with your tablet. For
more safety practices information, see the Regulatory Compliance Homepage
CAUTION: All repairs must be done by a certified service technician. Perform troubleshooting and simple repairs
as authorized in your product documentation, or as directed by the online or telephone service and support
team. Damage due to servicing that is not authorized by Dell is not covered by your warranty. Read and follow
the safety instructions that came with the product.
CAUTION: To avoid electrostatic discharge, ground yourself by using a wrist grounding strap or by periodically
touching an unpainted metal surface simultaneously as touching a connector on the back of the tablet.
CAUTION: Handle components and cards with care. Do not touch the components or contacts on a card. Hold a
card by its edges or by its metal mounting bracket. Hold a component such as a processor by its edges, not by
its pins.
CAUTION: When you disconnect a cable, pull on its connector or on its pull-tab, not on the cable itself. Some
cables have connectors with locking tabs; if you are disconnecting this type of cable, press in on the locking
tabs before you disconnect the cable. As you pull connectors apart, keep them evenly aligned to avoid bending
any connector pins. Also, before you connect a cable, ensure that both connectors are correctly oriented and
aligned.
NOTE: The color of your tablet and certain components may appear differently than shown in this document.
Before working inside the tablet
About this task
CAUTION: If ATEX label is missing or damaged, the system must not be repaired or recertified by the Service
Facility.
WARNING: Repair must be performed by a IECEx Certified Service Facility to maintain IECEx certification.
To avoid damaging your tablet, perform the following steps before you begin working inside the tablet:
1
Working on your tablet 5

Steps
1. Ensure that you follow the Safety Instruction.
2. Ensure that your work surface is flat and clean to prevent the tablet cover from being scratched.
3. Turn off your tablet.
4. Disconnect your tablet and all attached devices from their electrical outlets.
5. Press and hold the power button while the tablet is unplugged to ground the system board.
NOTE: To avoid electrostatic discharge, ground yourself by using a wrist grounding strap or by periodically touching an
unpainted metal surface simultaneously as touching a connector on the back of the tablet.
6. Remove any installed ExpressCards or Smart Cards from the appropriate slots.
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 tablet and all attached peripherals.
●Disconnect the tablet 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 tablet to avoid electrostatic discharge (ESD) damage.
●After removing any system component, carefully place the removed component on an antistatic mat.
●Wear shoes with nonconductive rubber soles to reduce the chance of getting electrocuted.
Bonding
Bonding is a method for connecting two or more grounding conductors to the same electrical potential. This is done by using 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 nonmetal 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:
●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.
6Working on your tablet

●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.
Working on your tablet 7

After working inside the tablet
About this task
After you complete any replacement procedure, ensure that you connect external devices, cards, and cables before turning on
your tablet.
CAUTION: To avoid damage to the tablet, use only the battery that is designed for this particular Dell tablet. Do
not use batteries that are designed for other Dell tablets.
Steps
1. Connect any external devices, such as a mobile keyboard or a docking station, and replace any cards, such as an
ExpressCard.
2. Connect your tablet and all attached devices to their electrical outlets.
3. Turn on your tablet.
8 Working on your tablet

Major components of the tablet
1. Display assembly
2. Coin-cell battery
2
Major components of the tablet 9

3. WLAN card
4. WWAN card
5. Heat-sink
6. USB Type-C bracket
7. Mini-serial bracket
8. Power adapter port
9. Mini-serial port
10. System board
11. NFC antenna
12. System cover
13. Left battery (as viewed from the back)
14. Right battery (as viewed from the back)
15. Battery cover assembly
16. Microphone assembly circuit board
17. System fan
18. Solid-state drive
19. Front camera cable
20. Front camera cover
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.
10 Major components of the tablet

Field service information
Topics:
•Safety instructions
•Recommended tools
•Screw list
•Customer Replaceable Units (CRU) and Field Replaceable Units (FRU) list
•Disassembly and reassembly
Safety instructions
Prerequisites
Use the following safety guidelines to protect your tablet from potential damage and to ensure your personal safety. Unless
otherwise noted, each procedure in this document assumes that the following conditions exist:
●You have read the safety information that shipped with your tablet.
●A component can be replaced or, if purchased separately, installed by performing the removal procedure in reverse order.
About this task
NOTE: Disconnect all power sources before opening the tablet. After you finish working inside your tablet, replace all the
components and screws before connection the power source.
WARNING: Before working inside your tablet, read the safety information that shipped with your tablet. For
more safety practices information, see the Regulatory Compliance Homepage
CAUTION: All repairs must be done by a certified service technician. Perform troubleshooting and simple repairs
as authorized in your product documentation, or as directed by the online or telephone service and support
team. Damage due to servicing that is not authorized by Dell is not covered by your warranty. Read and follow
the safety instructions that came with the product.
CAUTION: To avoid electrostatic discharge, ground yourself by using a wrist grounding strap or by periodically
touching an unpainted metal surface simultaneously as touching a connector on the back of the tablet.
CAUTION: Handle components and cards with care. Do not touch the components or contacts on a card. Hold a
card by its edges or by its metal mounting bracket. Hold a component such as a processor by its edges, not by
its pins.
CAUTION: When you disconnect a cable, pull on its connector or on its pull-tab, not on the cable itself. Some
cables have connectors with locking tabs; if you are disconnecting this type of cable, press in on the locking
tabs before you disconnect the cable. As you pull connectors apart, keep them evenly aligned to avoid bending
any connector pins. Also, before you connect a cable, ensure that both connectors are correctly oriented and
aligned.
NOTE: The color of your tablet and certain components may appear differently than shown in this document.
3
Field service information 11

Before working inside the tablet
About this task
CAUTION: If ATEX label is missing or damaged, the system must not be repaired or recertified by the Service
Facility.
WARNING: Repair must be performed by a IECEx Certified Service Facility to maintain IECEx certification.
To avoid damaging your tablet, perform the following steps before you begin working inside the tablet:
Steps
1. Ensure that you follow the Safety Instruction.
2. Ensure that your work surface is flat and clean to prevent the tablet cover from being scratched.
3. Turn off your tablet.
4. Disconnect your tablet and all attached devices from their electrical outlets.
5. Press and hold the power button while the tablet is unplugged to ground the system board.
NOTE: To avoid electrostatic discharge, ground yourself by using a wrist grounding strap or by periodically touching an
unpainted metal surface simultaneously as touching a connector on the back of the tablet.
6. Remove any installed ExpressCards or Smart Cards from the appropriate slots.
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 tablet and all attached peripherals.
●Disconnect the tablet 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 tablet to avoid electrostatic discharge (ESD) damage.
●After removing any system component, carefully place the removed component on an antistatic mat.
●Wear shoes with nonconductive rubber soles to reduce the chance of getting electrocuted.
Bonding
Bonding is a method for connecting two or more grounding conductors to the same electrical potential. This is done by using 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 nonmetal 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.
12 Field service information

●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:
●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.
User warning guide
CAUTION: All repairs must be done by a certified service technician. Opening the tablet violates ATEX/IECEx
certifications and warranties. You should only perform troubleshooting and simple repairs as authorized in
your product documentation, or as directed by online or telephone service and support team. Damage due to
servicing that is not authorized by Dell is not covered by your warranty. Read and follow the safety instructions
that came with the product.
WARNING: The battery must only be charged outside of any potentially explosive environment with appropriate
Dell power adapters.
WARNING: The I/O and battery bay covers must be closed with both screws tightened before the system is
exposed to a potentially explosive environment.
WARNING: Do not remove the battery or access the I/O ports while the system is exposed to a potentially
explosive environment.
WARNING: Do not connect external devices to any of the system ports while the system is exposed to a
potentially explosive environment.
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
Field service information 13

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.
After working inside the tablet
About this task
After you complete any replacement procedure, ensure that you connect external devices, cards, and cables before turning on
your tablet.
CAUTION: To avoid damage to the tablet, use only the battery that is designed for this particular Dell tablet. Do
not use batteries that are designed for other Dell tablets.
Steps
1. Connect any external devices, such as a mobile keyboard or a docking station, and replace any cards, such as an
ExpressCard.
2. Connect your tablet and all attached devices to their electrical outlets.
3. Turn on your tablet.
Recommended tools
The procedures in this document require the following tools:
●Phillips #0 screwdriver
●Phillips #1 screwdriver
●Philips #2 screwdriver
●Torx screwdriver T6
●Torx screwdriver T8
●Torx screwdriver T10
●Plastic scribe
NOTE: The #0 screw driver is for screws 0-1, and the #1 screw driver is for screws 2-4.
14 Field service information

Screw list
NOTE: When removing screws from a component, it is recommended to note the screw type, the quantity of screws, and
then place them in a screw storage box. This is to ensure that the correct number of screws and correct screw type is
restored when the component is replaced.
NOTE: Screw color may vary with the configuration ordered.
Table 1. Screw list
Component Screw type Quantity Screw image
Latitude 7220EX armor
assembly
M2.5x10
M2x6
M4x7
8
12
1
Latitude 7220EX battery cover
assembly
M4x11.5 2 Captive screws
Latitude 7220EX armor door M3.5x11 2 Captive screws
LCD M2.5x5 11
Function keys M2x5 6
SSD Heat-sink M2x5
M2x3
1
3
System fan M2x5 4
Solid-state drive (SSD) M2x3 1
M.2 WLAN M2x3 1
M.2 WWAN M2x3 1
Microphone M2x5 2
Front camera M2x5 1
Field service information 15

Table 1. Screw list (continued)
Component Screw type Quantity Screw image
System board M2x5
M2x3
M1.6x5
11
2
2
Rear camera M2x5 3
Micro serial port and power
connector port
M2x5
M1.6x5
6
2
Docking Board M2x5 5
Smart card reader and wireless
passthrough daughterboard
M2x5 10
Customer Replaceable Units (CRU) and Field
Replaceable Units (FRU) list
Table 2. CRU/FRU list
CRU component FRU component
Battery
Stylus
Batteries cover assembly
System cover
SIM card
Camera shutter
16 Field service information

Table 2. CRU/FRU list (continued)
CRU component FRU component
Heat sink
Fan assembly
LCD assembly
Bottom base assembly
Front camera
Rear camera
M.2 WLAN card
M.2 WWAN card
M.2 SSD
Power button assembly
Microphone
Coin-cell battery
System board
Disassembly and reassembly
NOTE: The images in this document may differ from your computer depending on the configuration you ordered.
Field service information 17

Batteries cover assembly
Removing the batteries cover assembly
Prerequisites
1. Follow the procedure in before working inside the tablet.
About this task
The figure indicates the location of the batteries cover assembly and provides a visual representation of the removal procedure.
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Steps
1. Lift the handle of the two (M4x11.5) captive screws.
2. Loosen the two (M4x11.5) captive screws that secure the battery cover assembly to the chassis.
3. Slide the battery cover assembly away from the chassis.
4. Remove the battery cover assembly from the tablet.
Installing the batteries cover assembly
Prerequisites
If you are replacing a component, remove the existing component before performing the installation procedure.
About this task
The figure indicates the location of the batteries cover assembly and provides a visual representation of the installation
procedure.
Field service information 19

20 Field service information