Lenovo ThinkPad X23 ThinkPad X20, X21, X22, X23, X24 Hardware Maintenance Manu - Page 56

LCD-related symptoms, Intermittent problems, Important, SVGAX20, X21, XGAX22, X23, X24

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The power-on password prompt A power-on password or a supervisor password is set. Type the password and press Enter. The hard disk password prompt A hard disk password is set. Type the password and press Enter. The DOS-full screen looks smaller. Start the ThinkPad Configuration program and set the Screen expansion function. LCD-related symptoms Important: The TFT LCD for the notebook computer contains many thin-film transistors (TFTs). 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: v SVGA(X20, X21): 5 or more bright dots, 5 or more dark dots, or a total of 9 or more bright and dark dots. v XGA(X22, X23, X24): 8 or more bright dots, 8 or more dark dots, or a total of 9 or more bright and dark dots. 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 v Horizontal or vertical lines displayed on LCD FRU or action, in sequence 1. 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. 1. LCD assembly. Intermittent problems Intermittent system hang problems can be due to a variety of causes that have nothing to do with a hardware defect, 52 ThinkPad X20, X21, X22, X23, X24

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The power-on password prompt
A power-on password or a
supervisor password is set.
Type the password and press
Enter
.
The hard disk password prompt
A hard disk password is set.
Type the password and press
Enter
.
The DOS-full screen looks
smaller.
Start the ThinkPad
Configuration program and set
the
Screen expansion
function.
LCD-related symptoms
Important:
The TFT LCD for the notebook computer contains many
thin-film transistors (TFTs). 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:
v
SVGA(X20, X21):
5 or more bright dots, 5 or more dark
dots, or a total of 9 or more bright and dark dots.
v
XGA(X22, X23, X24):
8 or more bright dots, 8 or more
dark dots, or a total of 9 or more bright and dark dots.
Symptom or error
FRU or action, in sequence
No beep, power-on indicator
on, and a blank LCD during
POST
1.
System board.
v
LCD backlight not working
v
LCD too dark
v
LCD brightness cannot be
adjusted
v
LCD contrast cannot be
adjusted
1.
Reseat the LCD
connectors.
2.
LCD assembly.
3.
System board.
v
LCD screen unreadable
v
Characters missing pixels
v
Screen abnormal
v
Wrong color displayed
1.
See important note for
″
LCD-related symptoms
″
.
2.
Reseat all LCD connectors.
3.
LCD assembly.
v
Horizontal or vertical lines
displayed on LCD
1.
LCD assembly.
Intermittent problems
Intermittent system hang problems can be due to a variety
of causes that have nothing to do with a hardware defect,
52
ThinkPad X20, X21, X22, X23, X24