Toshiba Portege M200 Maintenance Manual page 79

2.8 Display Troubleshooting
Procedure 4 Replacement Check
The display unit has a FL inverter board, Display module, System board, LCD harness and
Display ON/OFF switch. Any of the components may be damaged. Disassemble the computer
following the steps described in Chapter 4, Replacement Procedures, then perform the
following checks:
(1) If characters or graphics are not displayed on the internal display, perform Check 1.
(2) If characters are displayed on the internal display but the display is not normal,
perform Check 2.
(3) If characters are displayed on the internal display but the display is dark (the back-light
does not light), perform Check 5.
Check 1 The display ON/OFF switch may be damaged. Remove the display ON/OFF
switch and repeat Procedure 4. If there is still an error, go to Check 2.
Check 2 The LCD harness may be damaged. Replace the damaged harness with a new one
and repeat Procedure 4. If there is still an error, go to Check 3.
Check 3 The display module may be damaged. Replace it with a new one and repeat
Procedure 4. If there is still an error, go to Check 4.
Check 4 The FL inverter board may be damaged. Replace it with a new one and repeat
Procedure 4. If there is still an error, go to Check 5.
Check 5 The FL tube may be damaged. Replace it with a new one and repeat Procedure 4.
If there is still an error, go to Check 6.
Check 6 The display controller of the system board may be damaged. Replace the system
board with a new one.
Portege M200 Maintenance Manual (960-457)
2 Troubleshooting
2-41