LCD-related  symptoms 
 
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: 
v  XGA:  8  or  more  bright  dots,  8  or  more  dark  dots, 
or  a  total  of  9  or  more  bright  and  dark  dots. 
v  SXGA+:  11  or  more  bright  dots,  13  or  more  dark 
dots,  or  a  total  of  16  or  more  bright  and  dark 
dots. 
v  UXGA:  11  or  more  bright  dots,  16  or  more  dark 
dots,  or  a  total  of  16  or  more  bright  and  dark 
dots. 
v  QXGA:  15  or  more  bright  dots,  16  or  more  dark 
dots,  or  a  total  of  16  or  more  bright  and  dark 
dots.
Note:
  A  bright  dot  means  a  pixel  is  always  on 
(white  or  color.)  A  dark  dot  means  a  pixel  is 
always  off  (black  color.) 
 
Symptom  or  error  FRU  or  action,  in  sequence 
No  beep,  power-on  indicator 
on,  and  a  blank  LCD  during 
POST. 
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. 
4.  System  board. 
Horizontal  or  vertical  lines 
displayed  on  LCD. 
LCD  assembly. 
 
Symptom-to-FRU  index 
ThinkPad  R50/R50p  and  R51  Series  61