IBM 1412 - Manual (Page 29)

Modem-Related Symptoms
Symptom/Error FRU/Action in Sequence
Internal modem does
not work correctly Go to “Modem Board Check”
on page 12.
Modem connector
Modem board
Planar board
Intermittent Problems
Intermittent system hang problems can be caused by a
variety of reasons that have nothing to do with a hardware
defect, such as cosmic radiation, electronic discharge, or
software errors. FRU replacement should only be consid-
ered when a recurring problem exists.
When analyzing the intermittent problem, do the following:
1. Run the diagnostic test for the planar 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 inop-
erative. 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 cir-
cuits 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/DVD-ROM drive
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.
ThinkPad i Series 1400 25