IBM PS/1, Hardware Maintenance Service

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MAP 0020:
Power
Symptom Explanation
Conditions That Could Cause This
Symptom
You have entered this
MAP because you were
unable to complete
POST, another MAP
directed you here, or you
suspect a power
problem. A diskette drive is failing.
A hard disk drive is failing.
A memory card (SIMM) is failing.
A video RAM is failing (486SX 30-pin
memory SIMM) on system board only.
The riser card is failing.
The power supply is failing.
The system board is failing.
The math coprocessor is failing
(386SX or 486SX).
001
– Power off the system unit.
– Unplug the system unit power cord, the display power cord, and any
external devices from the electrical outlets.
– Disconnect all external cables and devices from the system unit, except
for the keyboard, mouse, and display.
– Remove all adapter cards from the riser card.
– Disconnect any drives except for the following:
Machine Type 2133
– One 3.5-in. diskette drive
– One 5.25-in. diskette drive
– One hard disk drive.
Machine Type 2155 or Machine Type 2168
– One 3.5-in. diskette drive
– One 5.25-in. diskette drive
– Two hard disk drives. (Some machines have one hard disk drive
installed.)
(Step 001 continues)
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