IBM R31 - Manual (Page 55)

1. Run the diagnostic test for the system board at least
10 times.
2. If no error is detected, do not replace any FRUs.
3. If any error is detected, replace the FRU. Rerun the
test to verify that there are no more errors.
Undetermined Problems
The diagnostic tests did not identify which adapter or
device failed, which installed devices are incorrect, whether
a short circuit is suspected, or whether the system is
inoperative. Follow the procedures below to isolate the
failing FRU.
Verify that the power supply being used at the time of the
failure is operating correctly.
1. Power off the computer.
2. Check the cables, wires, and connectors for short
circuits and open circuits. Visually check them for
damage. If any problems are found, replace the FRU.
3. Remove or disconnect all of the following devices:
v Non-IBM devices
v Printer, external mouse & keyboard, and other
external devices
v Battery pack
v Hard disk drive
v CD-ROM drive/Diskette drive (optional)
v PC Card (PCMCIA)
4. Power on the computer.
5. Determine if the problem has changed.
6. If the problem does not occur again, reconnect the
removed devices one at a time until you find the failing
FRU.
7. If the problem remains, replace the following FRUs one
at a time. Do not replace a non-defective FRU.
v Hard disk drive connection board
v LCD assembly
v System board
MT 2656, 2657, 2676 49