Lenovo Chromebook C340-15 Owner's manual

Lenovo Chromebook C340-15
Hardware Maintenance Manual

First Edition (June 2019)
© Copyright Lenovo 2019.

Contents
About this m nu l . . . . . . . . . . . . iii
Ch pter 1. S fety inform tion . . . . . . 1
General safet . . . . . . . . . . . . . . . . 1
Electrical safet . . . . . . . . . . . . . . . . 1
Safet inspection guide . . . . . . . . . . . . . 2
Handling devices that are sensitive to electrostatic
discharge . . . . . . . . . . . . . . . . . . 3
Grounding requirements . . . . . . . . . . . . 4
Safet notices (multilingual translations) . . . . . . 4
Ch pter 2. Gener l checkout . . . . . 21
What to do first . . . . . . . . . . . . . . . 21
CRU list . . . . . . . . . . . . . . . . . . 22
Ch pter 3. Cre te nd use USB
rep ir shim . . . . . . . . . . . . . . . 23
What is a USB repair shim? . . . . . . . . . . 23
Create a repair shim . . . . . . . . . . . . . 23
Use a USB repair shim to diagnose and fix
problems . . . . . . . . . . . . . . . . . 23
Factor test items . . . . . . . . . . . . 24
Ch pter 4. Idetifying FRUs (CRUs) . . 27
Locate FRU and CRU . . . . . . . . . . . . 27
Ch pter 5. Removing FRU or
CRU . . . . . . . . . . . . . . . . . . 31
Service tools . . . . . . . . . . . . . . . . 31
General guidelines. . . . . . . . . . . . . . 31
Remove the lower case . . . . . . . . . . . . 32
Remove the batter pack . . . . . . . . . . . 33
Remove the WLAN card . . . . . . . . . . . 34
Remove the upper case. . . . . . . . . . . . 36
Remove the fan . . . . . . . . . . . . . . . 37
Remove the I/O board with cable . . . . . . . . 38
Remove the heat sink . . . . . . . . . . . . 40
Remove the speakers . . . . . . . . . . . . 41
Remove the s stem board. . . . . . . . . . . 42
Remove the LCD module . . . . . . . . . . . 44
Remove the camera and sensor board . . . . . . 46
Trademarks . . . . . . . . . . . . . . . . xlix
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ii Lenovo Chromebook C340-15 Hardware Maintenance Manual

About this m nu l
This manual contains service and reference information for the following Lenovo products.
M chine M chine type (MT)
Lenovo Chromebook C340-15 81T9
Import nt:
• This manual is intended onl 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 “Safet
information” on page 1.
© Cop right Lenovo 2019 iii

iv Lenovo Chromebook C340-15 Hardware Maintenance Manual

Ch pter 1. S fety inform tion
This chapter presents the following safet information that ou need to be familiar with before ou service a
Lenovo notebook computer.
Gener l s fety
Follow these rules to ensure general safet :
• Observe good housekeeping in the area of the machines during and after maintenance.
• When lifting an heav object:
1. Make sure that ou can stand safel without slipping.
2. Distribute the weight of the object equall between our feet.
3. Use a slow lifting force. Never move suddenl or twist when ou attempt to lift.
4. Lift b standing or b pushing up with our leg muscles; this action removes the strain from the
muscles in our 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 an action that causes hazards to the customer, or that makes the equipment unsafe.
• Before ou 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, awa from all personnel, while ou are servicing the
machine.
• Keep our tool case awa 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 our
sleeves are fastened or rolled up above our elbows. If our hair is long, fasten it.
• Insert the ends of our necktie or scarf inside clothing or fasten it with a non-conductive clip, about 8
centimeters (3 inches) from the end.
• Do not wear jewelr , chains, metal-frame e eglasses, or metal fasteners for our clothing.
Attention: Metal objects are good electrical conductors.
• Wear safet glasses when ou are hammering, drilling, soldering, cutting wire, attaching springs, using
solvents, or working in an other conditions that might be hazardous to our e es.
• After service, reinstall all safet shields, guards, labels, and ground wires. Replace an safet device that
is worn or defective.
• Reinstall all covers correctl 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.
Electric l s fety
Observe the following rules when working on electrical equipment.
Import nt: Use onl approved tools and test equipment. Some hand tools have handles covered with a soft
material that does not insulate ou when working with live electrical currents.Man customers have, near
their equipment, rubber floor mats that contain small conductive fibers to decrease electrostatic discharges.
Do not use this t pe of mat to protect ourself from electrical shock.
• Find the room emergenc power-off (EPO) switch, disconnecting switch, or electrical outlet. If an electrical
accident occurs, ou can then operate the switch or unplug the power cord quickl .
• 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
© Cop right Lenovo 2019 1

– Removing or installing main units
• Before ou start to work on the machine, unplug the power cord. If ou 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 ou 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 ou.
Attention: Another person must be there to switch off the power, if necessar .
– Use onl one hand when working with powered-on electrical equipment; keep the other hand in our
pocket or behind our back.
Attention: An electrical shock can occur onl when there is a complete circuit. B observing the above
rule, ou ma prevent a current from passing through our bod .
– When using testers, set the controls correctl and use the approved probe leads and accessories for
that tester.
– Stand on suitable rubber mats (obtained locall , if necessar ) to insulate ou from grounds such as
metal floor strips and machine frames.
Observe the special safet precautions when ou work with ver high voltages; Instructions for these
precautions are in the safet sections of maintenance information. Use extreme care when measuring high
voltages.
• Regularl inspect and maintain our 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.
• Alwa s look carefull for possible hazards in our work area. Examples of these hazards are moist floors,
non-grounded power extension cables, power surges, and missing safet 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 injur and machine damage.
• Do not service the following parts with the power on when the are removed from their normal operating
places in a machine:
– Power suppl units
– Pumps
– Blowers and fans
– Motor generators
– Similar units as listed above
This practice ensures correct grounding of the units.
• If an electrical accident occurs:
– Use caution; do not become a victim ourself.
– Switch off power.
– Send another person to get medical aid.
S fety inspection guide
The purpose of this inspection guide is to assist ou in identif ing potentiall unsafe conditions. As each
machine was designed and built, required safet items were installed to protect users and service
technicians from injur . This guide addresses onl those items. You should use good judgment to identif
potential safet hazards due to attachment of non-Lenovo features or options not covered b this inspection
guide.
If an unsafe conditions are present, ou must determine how serious the apparent hazard could be and
whether ou can continue without first correcting the problem.
Consider these conditions and the safet hazards the present:
• Electrical hazards, especiall primar power (primar voltage on the frame can cause serious or fatal
electrical shock)
• Explosive hazards, such as a damaged cathode ra tube (CRT) face or a bulging capacitor
• Mechanical hazards, such as loose or missing hardware
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To determine whether there are an potentiall unsafe conditions, use the following checklist at the
beginning of ever 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
continuit for 0.1 ohm or less between the external ground pin and the frame ground.
b. The power cord should be the authorized t pe specified for our computer. Go to: http://
www.lenovo.com/serviceparts-lookup
c. Insulation must not be fra ed or worn.
4. Check for cracked or bulging batteries.
5. Remove the cover.
6. Check for an obvious non-Lenovo alterations. Use good judgment as to the safet of an non-Lenovo
alterations.
7. Check inside the unit for an obvious unsafe conditions, such as metal filings, contamination, water or
other liquids, or signs of fire or smoke damage.
8. Check for worn, fra ed, or pinched cables.
9. Check that the power-suppl cover fasteners (screws or rivets) have not been removed or tampered
with.
H ndling devices th t re sensitive to electrost tic disch rge
An computer part containing transistors or integrated circuits (ICs) should be considered sensitive to
electrostatic discharge (ESD). ESD damage can occur when there is a difference in charge between objects.
Protect against ESD damage b equalizing the charge so that the machine, the part, the work mat, and the
person handling the part are all at the same charge.
Notes:
1. Use product-specific ESD procedures when the exceed the requirements noted here.
2. Make sure that the ESD protective devices ou use have been certified (ISO 9000) as full effective.
When handling ESD-sensitive parts:
• Keep the parts in protective packages until the are inserted into the product.
• Avoid contact with other people.
• Wear a grounded wrist strap against our skin to eliminate static on our bod .
• Prevent the part from touching our clothing. Most clothing is insulative and retains a charge even when
ou are wearing a wrist strap.
• Use a grounded work mat to provide a static-free work surface. The mat is especiall useful when
handling ESD-sensitive devices.
• Select a grounding s stem, such as those listed below, to provide protection that meets the specific
service requirement.
Note: The use of a grounding s stem to guard against ESD damage is desirable but not necessar .
– Attach the ESD ground clip to an frame ground, ground braid, or green-wire ground.
– When working on a double-insulated or batter -operated s stem, use an ESD common ground or
reference point. You can use coax or connector-outside shells on these s stems.
– Use the round ground prong of the ac plug on ac-operated computers.
Chapter 1.Safet information 3

Grounding requirements
Electrical grounding of the computer is required for operator safet and correct s stem function. Proper
grounding of the electrical outlet can be verified b a certified electrician.
S fety notices (multilingu l tr nsl tions)
The safet notices in this section are provided in the following languages:
• English
• Arabic
• Brazilian Portuguese
• French
• German
• Hebrew
• Japanese
• Korean
• Spanish
• Traditional Chinese
DANGER
DANGER
DANGER
4Lenovo Chromebook C340-15 Hardware Maintenance Manual

DANGER
DANGER
DANGER
DANGER
DANGER
Chapter 1.Safet information 5

6Lenovo Chromebook C340-15 Hardware Maintenance Manual

PERIGO
PERIGO
PERIGO
Chapter 1.Safet information 7

PERIGO
PERIGO
PERIGO
PERIGO
PERIGO
8Lenovo Chromebook C340-15 Hardware Maintenance Manual

DANGER
DANGER
DANGER
DANGER
Chapter 1.Safet information 9

DANGER
DANGER
DANGER
DANGER
VORSICHT
10 Lenovo Chromebook C340-15 Hardware Maintenance Manual

VORSICHT
VORSICHT
VORSICHT
VORSICHT
Chapter 1.Safet information 11

VORSICHT
VORSICHT
VORSICHT
12 Lenovo Chromebook C340-15 Hardware Maintenance Manual

Chapter 1.Safet information 13

14 Lenovo Chromebook C340-15 Hardware Maintenance Manual