IBM 310ED - Manual (Page 47)

Undetermined Problems
You are here because the diagnostic tests did not identify
which adapter or device failed, installed devices are
incorrect, a short circuit is suspected, or 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:
Non-IBM devices
Printer, external mouse, keyboard, and other
external devices
Battery pack
Hard disk drive
Diskette drive/CD-ROM drive
DIMM
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.
Keyboard Connector Board
Charger Board
Audio Connector Board
LCD Assembly
System Board
ThinkPad 310, 310D, 310E, 310ED (2600) 23