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
NOTE: Verify that the power supply being used at the time of the failure is operating correctly. (See “Power On Issue” on page 150.):
1.
2.Visually check them for damage. If any problems are found, replace the FRU.
3.Remove or disconnect all of the following devices:
•
•Printer, mouse, and other external devices
•Battery pack
•Hard disk drive
•DIMM
•
•PC Cards
4.
5.Determine if the problem has changed.
6.If the problem does not recur, reconnect the removed devices one at a time until you find the failing FRU.
7.If the problem remains, replace the following FRU one at a time. Do not replace a
•System board
•LCD assembly
160 | Chapter 4 |
