98 Troubleshooting
Note: I f you cannot find a symptom or an error in this list and the
problem remains, see “Undetermined Problems” on page 56.
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,
electrostatic discharge, or software errors. FRU replacement should be
considered only when a recurring problem exists.
When analyzing an intermittent problem, do the following:
1. Run the advanced diagnostic test for the system board in loop mode at
least 10 times.
2. If no error is detected, do not replace any FRU.
3. If any error is detected, replace the FRU. Rerun the test to verify that
there are no more errors.
Undetermined Problems
The diagnostic problems does 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 these procedures to isolate the failing FRU (do not isolate non-
defective FRU).
Note: Verify that all attached devices are supported by the computer.
Note: Verify that the power supply being used at the time of the failur e is
operating correctly. (See “Power System Check” on page 88):
1. Power-off the computer.
2. Visually check them for damage. If any problems are found, replace the
FRU.
Modem-Related Symptoms
Symptom / Error Action in Sequence
Internal modem does not
work correctly. See “System Diagnostic Diskette” on page 59.
Modem phone jack
Modem board
System board