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 personnel 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:
v Electrical hazards, especially primary power (primary
voltage on the frame can cause serious or fatal
electrical shock)
v Explosive hazards, such as a damaged CRT face or a
bulging capacitor
v 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. 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 type specified in the
parts list.

c. Insulation must not be frayed or worn.

4. Remove the cover.

5. Check for any obvious non-ThinkPad alterations. Use
good judgment as to the safety of any non-ThinkPad
alterations.
6. 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.
7. Check for worn, frayed, or pinched cables.
Safety information

Introduction 19