Lenovo ThinkBook 14 Gen 2 Owner's manual

Hardware Maintenance Manual
Lenovo ThinkBook 14 Gen 4+ and Lenovo ThinkBook 16 Gen 4+

First Edition (March 2022)
© Copyright Lenovo 2022.

Contents
About this manua . . . . . . . . . . . . iii
Chapter 1. Safety information . . . . . . 1
General safety . . . . . . . . . . . . . . . . 1
Electrical safety . . . . . . . . . . . . . . . . 1
afety inspection guide . . . . . . . . . . . . . 2
Handling devices that are sensitive to electrostatic
discharge . . . . . . . . . . . . . . . . . . 3
Grounding requirements . . . . . . . . . . . . 4
afety notices (multilingual translations) . . . . . . 4
Chapter 2. Genera checkout . . . . . 21
What to do first . . . . . . . . . . . . . . . 21
CRU list . . . . . . . . . . . . . . . . . . 22
Chapter 3. Identifying FRUs
(CRUs) . . . . . . . . . . . . . . . . . 23
Locate FRUs and CRUs . . . . . . . . . . . 23
Chapter 4. Removing a FRU or
CRU . . . . . . . . . . . . . . . . . . 33
ervice tools . . . . . . . . . . . . . . . . 33
General guidelines. . . . . . . . . . . . . . 33
Removal procedure for 14-inch models . . . . . 34
Remove the lower case . . . . . . . . . . 34
Remove the battery pack . . . . . . . . . 35
Remove the solid-state drive ( D) and solid-
state drive ( D) bracket . . . . . . . . . 36
Remove the Wi-Fi card . . . . . . . . . . 37
Remove the speakers. . . . . . . . . . . 38
Remove the heat sink. . . . . . . . . . . 39
Remove the fans . . . . . . . . . . . . 40
Remove the I/O board and the CMO
battery . . . . . . . . . . . . . . . . 41
Remove the fingerprint board cable . . . . . 42
Remove the touchpad cable . . . . . . . . 43
Remove the system board and the I/O board
cable . . . . . . . . . . . . . . . . . 44
Remove the LCD module . . . . . . . . . 47
Remove the upper case . . . . . . . . . . 48
Disassemble the LCD module . . . . . . . 48
Removal procedure for 16-inch models . . . . . 54
Remove the lower case . . . . . . . . . . 54
Remove the battery pack . . . . . . . . . 55
Remove the solid-state drive ( D) and solid-
state drive ( D) bracket . . . . . . . . . 55
Remove the Wi-Fi card . . . . . . . . . . 57
Remove the speakers. . . . . . . . . . . 57
Remove the heat sink. . . . . . . . . . . 58
Remove the fans . . . . . . . . . . . . 59
Remove the I/O board and the CMO
battery . . . . . . . . . . . . . . . . 60
Remove the fingerprint board cable . . . . . 62
Remove the touchpad cable . . . . . . . . 63
Remove the system board and the I/O board
cable . . . . . . . . . . . . . . . . . 64
Remove the LCD module . . . . . . . . . 67
Remove the upper case . . . . . . . . . . 68
Disassemble the LCD module . . . . . . . 68
Appendix A. Labe ocations. . . . . . 75
Trademarks . . . . . . . . . . . . . . . . lxxix
© Copyright Lenovo 2022 i

ii Hardware Maintenance Manual

About this manua
This manual contains service and reference information for the following Lenovo products.
Mode name Machine type (MT)
ThinkBook 14 G4+ IAP 21CX
ThinkBook 16 G4+ IAP 21CY
ThinkBook 14 G4+ ARA 21D0
ThinkBook 16 G4+ ARA 21D1
Important:
• This manual is intended only for trained service technicians who are familiar with Lenovo products.
• Before servicing a Lenovo product, be sure to read all the information under Chapter 1 “ afety
information” on page 1.
© Copyright Lenovo 2022 iii

iv Hardware Maintenance Manual

Chapter 1. Safety information
This chapter presents the following safety information that you need to be familiar with before you service a
Lenovo notebook computer.
Genera safety
Follow these rules to ensure general safety:
• Observe good housekeeping in the area of the machines during and after maintenance.
• When lifting any heavy object:
1. Make sure that you can stand safely without slipping.
2. Distribute the weight of the object equally between your feet.
3. Use a slow lifting force. Never move suddenly or twist when you attempt to lift.
4. Lift by standing or by pushing up with your leg muscles; this action removes the strain from the
muscles in your back. Do not attempt to lift any object that weighs more than 16 kg (35 lb) or that you
think is too heavy for you.
• Do not perform any action that causes hazards to the customer, or that makes the equipment unsafe.
• Before you start the machine, make sure that other service technicians and the customer's personnel are
not in a hazardous position.
• Place removed covers and other parts in a safe place, away from all personnel, while you are servicing the
machine.
• Keep your tool case away from walk areas so that other people will not trip over it.
• Do not wear loose clothing that can be trapped in the moving parts of a machine. Make sure that your
sleeves are fastened or rolled up above your elbows. If your hair is long, fasten it.
• Insert the ends of your necktie or scarf inside clothing or fasten it with a non-conductive clip, about 8
centimeters (3 inches) from the end.
• Do not wear jewelry, chains, metal-frame eyeglasses, or metal fasteners for your clothing.
Attention: Metal objects are good electrical conductors.
• Wear safety glasses when you are hammering, drilling, soldering, cutting wire, attaching springs, using
solvents, or working in any other conditions that might be hazardous to your eyes.
• After service, reinstall all safety shields, guards, labels, and ground wires. Replace any safety device that
is worn or defective.
• Reinstall all covers correctly before returning the machine to the customer.
• Fan louvers on the machine help to prevent overheating of internal components. Do not obstruct fan
louvers or cover them with labels or stickers.
E ectrica safety
Observe the following rules when working on electrical equipment.
Important: Use only approved tools and test equipment. ome hand tools have handles covered with a soft
material that does not insulate you when working with live electrical currents.Many customers have, near
their equipment, rubber floor mats that contain small conductive fibers to decrease electrostatic discharges.
Do not use this type of mat to protect yourself from electrical shock.
• Find the room emergency power-off (EPO) switch, disconnecting switch, or electrical outlet. If an electrical
accident occurs, you can then operate the switch or unplug the power cord quickly.
• Do not work alone under hazardous conditions or near equipment that has hazardous voltages.
• Disconnect all power before:
– Performing a mechanical inspection
– Working near power supplies
© Copyright Lenovo 2022 1

– Removing or installing main units
• Before you start to work on the machine, unplug the power cord. If you cannot unplug it, ask the customer
to power-off the wall box that supplies power to the machine, and to lock the wall box in the off position.
• If you need to work on a machine that has e posed electrical circuits, observe the following precautions:
– Ensure that another person, familiar with the power-off controls, is near you.
Attention: Another person must be there to switch off the power, if necessary.
– Use only one hand when working with powered-on electrical equipment; keep the other hand in your
pocket or behind your back.
Attention: An electrical shock can occur only when there is a complete circuit. By observing the above
rule, you may prevent a current from passing through your body.
– When using testers, set the controls correctly and use the approved probe leads and accessories for
that tester.
– tand on suitable rubber mats (obtained locally, if necessary) to insulate you from grounds such as
metal floor strips and machine frames.
Observe the special safety precautions when you work with very high voltages; Instructions for these
precautions are in the safety sections of maintenance information. Use extreme care when measuring high
voltages.
• Regularly inspect and maintain your electrical hand tools for safe operational condition.
• Do not use worn or broken tools and testers.
• Never assume that power has been disconnected from a circuit. First, check that it has been powered off.
• Always look carefully for possible hazards in your work area. Examples of these hazards are moist floors,
non-grounded power extension cables, power surges, and missing safety grounds.
• Do not touch live electrical circuits with the reflective surface of a plastic dental mirror. The surface is
conductive; such touching can cause personal injury and machine damage.
• Do not service the following parts with the power on when they are removed from their normal operating
places in a machine:
– Power supply units
– Pumps
– Blowers and fans
– Motor generators
– imilar units as listed above
This practice ensures correct grounding of the units.
• If an electrical accident occurs:
– Use caution; do not become a victim yourself.
– witch off power.
– end another person to get medical aid.
Safety inspection guide
The purpose of this inspection guide is to assist you in identifying potentially unsafe conditions. As each
machine was designed and built, required safety items were installed to protect users and service
technicians from injury. This guide addresses only those items. You should use good judgment to identify
potential safety hazards due to attachment of non-Lenovo features or options not covered by this inspection
guide.
If any unsafe conditions are present, you must determine how serious the apparent hazard could be and
whether you can continue without first correcting the problem.
Consider these conditions and the safety hazards they present:
• Electrical hazards, especially primary power (primary voltage on the frame can cause serious or fatal
electrical shock)
• Explosive hazards, such as a damaged cathode ray tube (CRT) face or a bulging capacitor
• Mechanical hazards, such as loose or missing hardware
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To determine whether there are any potentially unsafe conditions, use the following checklist at the
beginning of every service task. Begin the checks with the power off, and the power cord disconnected.
Checklist:
1. Check exterior covers for damage (loose, broken, or sharp edges).
2. Power off the computer. Disconnect the power cord.
3. Check the power cord for:
a. A third-wire ground connector in good condition. Use a meter to measure third-wire ground
continuity for 0.1 ohm or less between the external ground pin and the frame ground.
b. The power cord should be the authorized type specified for your computer. Go to: http://
www.lenovo.com/serviceparts-lookup
c. Insulation must not be frayed or worn.
4. Check for cracked or bulging batteries.
5. Remove the cover.
6. Check for any obvious non-Lenovo alterations. Use good judgment as to the safety of any non-Lenovo
alterations.
7. Check inside the unit for any obvious unsafe conditions, such as metal filings, contamination, water or
other liquids, or signs of fire or smoke damage.
8. Check for worn, frayed, or pinched cables.
9. Check that the power-supply cover fasteners (screws or rivets) have not been removed or tampered
with.
Hand ing devices that are sensitive to e ectrostatic discharge
Any computer part containing transistors or integrated circuits (ICs) should be considered sensitive to
electrostatic discharge (E D). E D damage can occur when there is a difference in charge between objects.
Protect against E D damage by equalizing the charge so that the machine, the part, the work mat, and the
person handling the part are all at the same charge.
Notes:
1. Use product-specific E D procedures when they exceed the requirements noted here.
2. Make sure that the E D protective devices you use have been certified (I O 9000) as fully effective.
When handling E D-sensitive parts:
• Keep the parts in protective packages until they are inserted into the product.
• Avoid contact with other people.
• Wear a grounded wrist strap against your skin to eliminate static on your body.
• Prevent the part from touching your clothing. Most clothing is insulative and retains a charge even when
you are wearing a wrist strap.
• Use a grounded work mat to provide a static-free work surface. The mat is especially useful when
handling E D-sensitive devices.
• elect a grounding system, such as those listed below, to provide protection that meets the specific
service requirement.
Note: The use of a grounding system to guard against E D damage is desirable but not necessary.
– Attach the E D ground clip to any frame ground, ground braid, or green-wire ground.
– When working on a double-insulated or battery-operated system, use an E D common ground or
reference point. You can use coax or connector-outside shells on these systems.
– Use the round ground prong of the ac plug on ac-operated computers.
Chapter 1.afety information 3

Grounding requirements
Electrical grounding of the computer is required for operator safety and correct system function. Proper
grounding of the electrical outlet can be verified by a certified electrician.
Safety notices (mu ti ingua trans ations)
The safety notices in this section are provided in the following languages:
• English
• Arabic
• Brazilian Portuguese
• French
• German
• Hebrew
• Japanese
• Korean
• panish
• Traditional Chinese
DANGER
DANGER
DANGER
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DANGER
DANGER
DANGER
DANGER
DANGER
Chapter 1.afety information 5

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PERIGO
PERIGO
PERIGO
Chapter 1.afety information 7

PERIGO
PERIGO
PERIGO
PERIGO
PERIGO
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DANGER
DANGER
DANGER
DANGER
Chapter 1.afety information 9

DANGER
DANGER
DANGER
DANGER
VORSICHT
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VORSICHT
VORSICHT
VORSICHT
VORSICHT
Chapter 1.afety information 11

VORSICHT
VORSICHT
VORSICHT
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Chapter 1.afety information 13

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