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 be considered
only when a recurring problem exists.
When analyzing an intermittent problem, do the following:
1. Run the advanced diagnostic test for the planar board
in loop mode at least 10 times.
2. If no error is detected, do not replace any FRUs.
3. If any error is detected, replace the FRU shown by
the FRU code.. Rerun the test to verify that no more
errors exist.
Undetermined Problems
You are here because 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 these procedures to
isolate the failing FRU (do not isolate nondefective FRUs).
Verify that the power supply being used at the time of the
failure is operating correctly. (See “Power System
Checkout” on page 28).
1. Power off the computer.
2. Visually check them for damage. If any problems are
found, replace the FRU.
3. Remove or disconnect all of the following devices:
a. Non-IBM devices
b. Devices attached to the ThinkPad Port
Replicator with Advanced Etherjet Feature
c. Printer, mouse, and other external devices
d. Battery ASM
e. Hard disk drive
f. DIMM
g. CD-ROM and Diskette Drive (FDD ASM) in the
Combobay (UltraBay FX)
h. PC Cards (PCMCIA)
4. Power on the computer.
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 FRUs
one at a time. Do not replace a non-defective FRU.
a. Planar board
b. LCD panel ASM
c. CPU card
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ThinkPad 390/i Series 1700
