Lcd-Related Symptoms - Lenovo ThinkPad T61 Hardware Maintenance Manual

LCD-related symptoms

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Important:The TFT LCD for the notebook computer contains many thin-film
transistors (TFTs). The presence of a small number of dots that are missing,
discolored, or always lighted is characteristic of TFT LCD technology, but
excessive pixel problems can cause viewing concerns. The LCD should be
replaced if the number of missing, discolored, or lighted dots in any background
is as follows:
Table 5. Minimum quantity of defective pixels required for LCD replacement on June 2006
or later manufactured ThinkPad
LCD resolution Bright dots
XGA, WXGA
WXGA+, SXGA+,
WSXGA+
UXGA, WUXGA,
QXGA
Notes:
v Lenovo will not provide replacement if the LCD is within specification as we
cannot guarantee that any replacement LCD will have zero pixel defects.
v A bright dot means a pixel is always on (white or color.)
v A dark dot means a pixel is always off (black color.)
v One pixel consists of R, G, B sub-pixels.
Table 6. LCD-related symptoms
Symptom or error
No beep, power-on indicator on, and a
blank LCD during POST.
v LCD backlight not working.
v LCD too dark.
v LCD brightness cannot be adjusted.
v LCD contrast cannot be adjusted.
v LCD screen unreadable.
v Characters missing pixels.
v Screen abnormal.
v Wrong color displayed.
Horizontal or vertical lines displayed on
LCD.
Dark dots
5 6
5 8
5 13
FRU or action, in sequence
System board.
1. Reseat the LCD connectors.
2. LCD assembly.
3. System board.
1. See important note for "LCD-related
symptoms."
2. Reseat all LCD connectors.
3. LCD assembly.
4. System board.
LCD assembly.
Bright and dark dots
6
10
13
45
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