IBM 390E User Manual
Symptom/Error
FRU/Action in Sequence
No beep during
POST but system
runs correctly.
POST but system
runs correctly.
Speaker
LCD-Related Symptoms
Symptom/Error
FRU/Action in Sequence
LCD backlight not
working
working
LCD too dark
LCD brightness
cannot be adjusted
cannot be adjusted
LCD contrast cannot
be adjusted
be adjusted
1. Reseat the LCD connector.
2. Check the LCD inverter ID
3. LCD FPC ASM
4. LCD inverter
5. LCD
6. System board
LCD screen unread-
able
able
Character missing
pels
pels
Screen abnormal
Wrong color dis-
played
played
1. Reseat the LCD connector.
2. Check the LCD inverter ID
3. LCD FPC ASM
4. LCD inverter
5. LCD
6. System board
LCD has extra hori-
zontal or vertical lines
displayed.
zontal or vertical lines
displayed.
1. Check the LCD inverter ID
2. LCD FPC ASM
3. LCD inverter
4. LCD
5. System board
Keyboard-Related Symptoms
Symptom/Error
FRU/Action in Sequence
Keyboard (one or
more keys) doesn't
work.
more keys) doesn't
work.
1. Reseat the keyboard cable.
2. Keyboard
3. System board
Indicator-Related Symptoms
Symptom/Error
FRU/Action in Sequence
Indicator incorrectly
remains off or on, but
system runs cor-
rectly.
remains off or on, but
system runs cor-
rectly.
1. Reseat the LED board.
2. LED board
3. System board
Power-Related Symptoms
Symptom/Error
FRU/Action in Sequence
Power shuts down
during operation.
during operation.
1. Battery
2. AC Adapter
3. DC/DC & Charger board ASM
4. System board
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ThinkPad 390E