IBM 8128 Computer Hardware User Manual


 
Undetermined problems
1. Power-off the computer.
2. Remove or disconnect the following components (if installed) one at a time.
a. Non-IBM devices
b. External devices (modem, printer, or mouse)
c. Any adapters
d. Riser card
e. Memory modules
f. Extended video memory
g. External Cache
h. External Cache RAM
i. Hard disk drive
j. Diskette drive
3.
Power-on the computer to re-test the system.
4. Repeat steps 1 through 3 until you isolate the failing device or adapter.
If all devices and adapters have been removed, and the problem persists,
continue to the next step.
5. Check the power supply voltages (see “Power supply connectors” on page 110).
If the voltages are within tolerance, continue with the next step. If the voltages
are not within tolerance, replace the power supply.
6. Replace the system board (see “Replacing the system board (all machine
types)” on page 61).
Chapter 7. Symptom-to-FRU Index 109