IBM PC 300, Maintenance Service Manual

Page: 80 / 163

80
Undetermined Problems
If an error code is present, go to “Index of Symptoms, Messages, Error Codes, or Beeps” on page 57. If no error code is
present, continue with this check. Check the power supply voltages (see “Power Supply Cable Connector Specifications" on
page 127). If the voltages are correct, return here and continue with the following steps:
1. Power off the system unit.
2. Perform the following checks, one by one, until you have isolated the problem FRU (refer to "Parts/Test Point Locations"
on page 111 for locations):
Load default settings in setup.
Check all system board jumper positions and switch settings.
Check all adapter card jumper positions.
Check all device jumper positions.
Check all cables and connectors for proper installation.
If the jumpers, switch, and voltage settings are correct, return here and continue:
3. Remove or disconnect the following, one at a time:
Non-IBM devices
External devices
Any adapters
Modem card, if installed
CD-ROM drive
Diskette drive
Hard disk drive
DIMM
Processor
System board
4. Power on the system unit.
5. Repeat steps 1 through 4 until you find the failed device or adapter.
6. If software related, reload software from Recovery CD.
If the symptom changes, go to “Index of Symptoms, Messages, Error Codes, or Beeps” on page 57 or to the check
procedure for the last item tested.
Replace the last item tested if the system operates normally after removing the last item.