IBM ThinkPad 570E, Hardware Manual

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Symptom-to-FRU index
Symptom or error FRU or action, in
sequence
No beep, power-on indicator
on, and a blank LCD during
POST 1. System board.
LCD backlight not
working
LCD too dark
LCD brightness cannot
be adjusted
LCD contrast cannot
be adjusted
1. Reseat the LCD
connectors..
2. LCD assembly.
3. System board.
LCD screen
unreadable
Characters missing
pixels
Screen abnormal
Wrong color displayed
1. See important note
for “LCD-related
symptoms.” .
2. Reseat all LCD
connectors.
3. LCD assembly.
4. System board.
LCD has extra horizontal or
vertical lines displayed 1. LCD assembly.
Intermittent problems
Intermittent system hang problems can be due to a variety
of causes 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 diagnostic test for the system 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, installed devices are
incorrect, a short circuit is suspected, or the system is
inoperative. Follow these procedures to isolate the failing
FRU (do not isolate nondefective FRUs).
Verify that all attached devices are supported by the
computer.
Verify that the power supply being used at the time of the
failure is operating correctly. (See “Power system
checkout” on page 29.)
1. Power off the computer.
2. Visually check each FRU for damage. Replace any
damaged FRU.
46
ThinkPad 570 and 570E Hardware Maintenance
Manual