Safety Inspection Guide - Lenovo 3000 N100 Hardware Maintenance Manual

v 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
and similar units. (This practice ensures correct grounding of the units.)
v If an electrical accident occurs:
– Use caution; do not become a victim yourself.
– Switch off power.
– Send 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 personnel from injury. This guide
addresses only those items. You should use good judgment to identify potential
safety hazards due to attachment of non-Lenovo 3000 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-Lenovo 3000 alterations. Use good judgment as to
the safety of any non-Lenovo 3000 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.
8. Check that the power-supply cover fasteners (screws or rivets) have not been
removed or tampered with.
Safety information
13
Introduction