Safety inspection guide
The purpose of this inspection guide is to assist you in identifying potentially unsafe conditions. As each
machine was designed and built, required safety items were installed to protect users and service technicians
from injury. This guide addresses only those items. You should use good judgment to identify potential
safety hazards due to attachment of non-ThinkPad features or options not covered by this inspection guide.
If any unsafe conditions are present, you must determine how serious the apparent hazard could be and
whether you can continue without first correcting the problem.
Consider these conditions and the safety hazards they present:
• Electrical hazards, especially primary power (primary voltage on the frame can cause serious or fatal
electrical shock)
• Explosive hazards, such as a damaged CRT face or a bulging capacitor
• Mechanical hazards, such as loose or missing hardware
To determine whether there are any potentially unsafe conditions, use the following checklist at the beginning
of every service task. Begin the checks with the power off and the power cord disconnected.
Checklist:
1. Check exterior covers for damage (loose, broken, or sharp edges).
2. Turn off the tablet.
3. Disable the built-in battery. See “Before servicing the tablet” on page 46.
4. Disconnect the power cord.
5. Check the power cord for the following:
a. Make sure that a third-wire ground connector is in good condition. Use a meter to measure the
third-wire ground continuity, and make sure that the continuity between the external ground pin and
the frame ground is 0.1 ohm or less.
b. The power cord is the type specified in the parts list.
c. Insulation is not frayed or worn.
6. Remove the liquid crystal display (LCD) module assembly.
7. Check for cracked or bulging built-in batteries.
8. Check for any obvious non-ThinkPad alterations. Use good judgment as to the safety of any
non-ThinkPad alterations.
9. 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.
10. Check for worn, frayed, or pinched cables.
11. Check that the built-in battery fasteners (screws or rivets) have not been removed or tampered with.
Handling devices that are sensitive to electrostatic discharge
Any tablet part containing transistors or integrated circuits (ICs) should be considered sensitive to
electrostatic discharge (ESD). ESD damage can occur when there is a difference in charge between objects.
Protect against ESD damage by equalizing the charge so that the machine, the part, the work mat, and the
person handling the part are all at the same charge.
Notes:
1. Use product-specific ESD procedures when they exceed the requirements noted here.
Chapter 1
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Safety information
3
Summary of Contents for 20E3
Page 1: ...ThinkPad 10 Hardware Maintenance Manual Machine Types 20E3 and 20E4 ...
Page 9: ...DANGER DANGER DANGER DANGER DANGER Chapter 1 Safety information 5 ...
Page 10: ...DANGER 6 ThinkPad 10 Hardware Maintenance Manual ...
Page 38: ...2 3 4 5 6 2 7 8 Chapter 7 Removing or replacing a FRU 49 ...