68 IBM Desktop System HMM
Power Supply
001 - START
• Power off (unplug) the system unit. Check t he
power cord for continuity. Replace if necessary.
•Check for the correct line voltage from the power
outlet, and verify that the voltage selector switch
(if present) is set to the correct voltage.
•Power on the system unit.
002 - DOES THE POWER SUPPLY FAN RUN?
(YES, GO TO STEP 003. NO, GO TO STEP 004.)
003 - DOES THE SYSTEM FAIL TO SHUT OFF
WHEN THE ON/OFF SWITCH IS PRESSED? (YES,
READ AHEAD. NO, GO TO STEP 005.)
•You might have a damaged on/off switch cable
assembly.
•Disconnect the on/off switch cable assembly
connector from the power supply connector and
take an ohm reading.
•Go to step 007.
004 -
•Disconnect the power cord from the back of the
system unit.
•Disconnect all power and switch cable connectors
from the system board and the power supply.
•Disconnect the power connectors to all drives.
•Connect any one of the power connector to system
board or drive as power load for driving up power
supply.
•Reconnect the power cord and turn on the power
supply.
005 - DOES THE POWER SUPPLY FAN RUN?
(YES, READ AHEAD. NO, GO TO STEP 009)
•With the system powered on and the power supply
fan running, check the voltages of the power
supply connectors for the system board and all
drive connectors, as shown in the following figures.