IBM 570 Manuale Hardware

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 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.

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.

ThinkPad 570 and 570E Hardware Maintenance

Manual