Explosive hazards, such as a damaged  CRT face or
bulging capacitor
Mechanical hazards, such as loose or  missing
hardware
The guide consists of a series  of steps presented in a
checklist. 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 frame ground.
b. The power cord  should be the appropriate type
as specified in the parts listings.
c. Insulation must not  be frayed or worn.
4. Remove the cover.
5. Check for any  obvious non-IBM alterations. Use
good judgment as to the safety  of any non-IBM
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.
    Related Service Information 335