Lenovo T430U manual Intermittent problems, Undetermined problems, Reseat the LCD connectors

Models: T430U

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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

FRU or action, in sequence

 

 

No beep, power-on indicator on, and a blank LCD during

System board.

POST.

 

 

 

 

 

• LCD backlight not working.

1.

Reseat the LCD connectors.

LCD too dark.

2.

LCD assembly.

• LCD brightness cannot be adjusted.

3.

System board.

• LCD contrast cannot be adjusted.

 

 

 

 

 

 

LCD screen unreadable.

1.

See important note for “LCD-related symptoms.”

Characters missing pixels.

2.

Reseat all LCD connectors.

Screen abnormal.

3.

LCD assembly.

Wrong color displayed.

4.

System board.

 

 

Horizontal or vertical lines displayed on LCD.

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, 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 28)

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.Hard disk drive

d.External diskette drive or optical drive

e.memory module on the left memory slot, if there is one

f.PC Cards

4.Turn on the computer.

5.Determine whether the problem has been solved.

6.If the problem does not recur, reconnect the removed devices one at a time until you find the failing FRU.

7.If the problem remains, replace the following FRUs one at a time (do not replace a nondefective FRU):

38Hardware Maintenance Manual

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Lenovo T430U manual Intermittent problems, Undetermined problems, Reseat the LCD connectors, LCD assembly