Toshiba Satellite L850D, Maintenance Manual

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2 Troubleshooting 2.7 Display
2-16 Satellite/Satellite Pro/C850D/C855D/L850D/L855D Maintenance Manual
2.7 Display
To check if the computer’s display is defective or malfunctioning, follow the troubleshooting
procedures below as instructed.
Procedure 1 External Monitor Check
Procedure 2 Test Program Check
Procedure 3 Connector Check and Replacement Check
Procedure 1 External Monitor Check
Connect an external monitor to the computer's external monitor port, then boot the computer.
The computer automatically detects the external monitor even if resume mode is enabled.
If the external monitor works correctly, the internal LCD or LCD cable may be faulty. Go to
Procedure 3.
If the external monitor appears to have the same problem as the internal monitor, the system
board may be faulty. Go to Procedure 2.
Procedure 2 Test Program Check
Insert the diagnostics bootable CD in the computer's CD ROM, turn on the computer and run
the test. See Chapter 3 for information on how to perform the test.
If an error is detected in the test, go to Procedure 3. If no error is detected, the display itself
is normal.
Procedure 3 Connector Check and Replacement Check
The display unit has an LCD module, LED Backlight module, panel close switch. Any of the
components or their connections may be defective. Disassemble the computer following
steps described in Chapter 4, and then perform the following checks:
(1)
If the LCD does not light, perform Check 1.
(2) If characters or graphics are not displayed normally, perform Check 4.
(3) If the LCD remains lit when the display is closed, the panel close switch may be
defective. Perform Check 5.
Check 1 Make sure the following cables have been firmly connected to the system
board .
If any of the cables is loose or off, reconnect it firmly and return to
Procedure 3. If there is still an error, perform Check 2.
Check 2 The LCD cable may be faulty. Replace it with a new one and return to
LCD
System board
CPU
LCD cable