Lcd-Related Symptoms; Intermittent Problems; Undetermined Problems - Lenovo ThinkPad X131e Hardware Maintenance Manual

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. If the LCD you are servicing has
two or less visible defective pixels, it should not be considered faulty. However, if the LCD has three or more
visible defective pixels, it will be deemed as defective by Lenovo and it should be replaced.
Notes:
• This policy applies to all ThinkPad notebook computers purchased on 1 January, 2008 or later.
• Lenovo will not provide replacement if the LCD is within specification as we cannot guarantee that any
replacement LCD will have zero pixel defects.
• One pixel consists of R, G, B sub-pixels.
Table 5. LCD-related symptoms
Symptom or error
No beep, power-on indicator on, and a blank LCD during
POST.
• LCD backlight not working
• LCD too dark
• LCD brightness cannot be adjusted.
• LCD contrast cannot be adjusted.
• LCD screen unreadable
• Characters missing pixels
• Screen abnormal
• Wrong color displayed
Horizontal or vertical lines displayed on LCD

Intermittent problems

Intermittent system hang problems can be due to a variety of causes that have nothing to do with a hardware
defect, such as cosmic radiation, electrostatic discharge, or software errors. FRU replacement should be
considered only when a problem recurs.

Undetermined problems

If the diagnostic tests did not identify the device that has failed, if wrong devices are installed, or if the
system simply is not operating, follow these procedures to isolate the failing FRU (do not isolate FRUs
that have no defects).
Verify that all attached devices are supported by the computer.
Verify that the power supply being used at the time of the failure is operating correctly. (See "Power system
checkout" on page 26)
1. Turn off the computer.
2. Visually check each FRU for damage. Replace any damaged FRU.
3. Remove or disconnect all of the following devices:
a. Non-ThinkPad devices
b. Printer, mouse, and other external devices
c. Battery pack
d. Hard disk drive or solid-state drive
e. External drive
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Hardware Maintenance Manual
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