IBM ThinkPad 340 Series Hardware Maintenance Manual page 233

LCD Related Symptoms
The TFT LCD of the notebook computers contain over
921 000 thin film transistors (TFTs). A small number of
missing, discolored or lighted dots (on all the time) is
characteristic of TFT LCD technology. Excessive pixel
problems can cause viewing concerns. The LCD should
be replaced if the number of missing or discolored, or
lighted dots in any colored background is 21 or more.
Symptom/Error
No beep, power-on indicator
on, and a blank LCD during
POST.
LCD backlight not
working, or
LCD too dark, or
LCD brightness cannot
be adjusted, or
LCD contrast cannot
be adjusted.
LCD screen
unreadable, or
Characters missing
pels, or
Screen abnormal, or
Wrong color displayed.
LCD has extra horizontal or
vertical lines displayed.
Keyboard/TrackPoint II Related
Symptoms
Symptom/Error
Keyboard (one or more
keys) does not work.
TrackPoint II does not work.
Pointer moves automatically
or does not work correctly.
ThinkPad 355x, 360x, 370C, 750x, 755C, 755Cs
FRU/Action
1. System Board
2. DC/DC Card
3. Processor Card (370C,
750Ce, 755C, and
755Cs)
1. Reseat the LCD
connectors.
2. LCD Assembly
3. Interposer Card
4. DC/DC Card
1. See the preceding
important note.
2. Reseat the all LCD
connectors
3. LCD Assembly
4. System Board
5. Interposer Card
1. LCD Assembly
FRU/Action
1. Reseat the three
keyboard cables.
2. Keyboard
3. Interposer Card
4. System Board
1. Go to "TrackPoint II
checkout" on
page 204.
2. Keyboard
3. Interposer Card
4. System Board
1. See "TrackPoint II
checkout" on
page 204.
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