LCD–Related Symptoms
Important
The TFT LCD on some models of this computer
contains over 1,440,000 thin-film transistors (TFTs). A
small number of missing, discolored, or lighted dots
(on all the time) is characteristic of TFT LCD
technology, but excessive pixel problems can cause
viewing concerns. The LCD should be replaced if the
number of dots satisfies the following condition:
The number of missing, discolored, or lighted
dots in any background is 21 or more.
Symptom / Error FRU / Action in Sequence
No beep, power-on
indicator on, and a
blank LCD during
POST.
1. System Board
2. CPU Card
LCD backlight
not working, or
LCD too dark, or
LCD brightness
cannot be
adjusted, or
LCD contrast
cannot be
adjusted.
1. Reseat the LCD connectors.
2. LCD Assembly
LCD screen
unreadable, or
Characters
missing pels, or
Screen
abnormal, or
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.
LCD Assembly
112 IBM Mobile Systems - ThinkPad HMM Volume 3