Toshiba 650CT Maintenance Manual page 51

Procedure 4 Replacement Check
The FL, FL inverter board, LCD module, and system board are connected to the display
circuits. Any of these components may be damaged. Refer to Chapter 4, Replacement Proce-
dures, for instructions on how to disassemble the computer, then perform the following
checks:
If the FL does not light, perform Check 1.
If characters are not displayed clearly, perform Check 3.
If some screen functions do not operate properly, perform Check 3.
If the FL remains lit when the display is closed, perform Check 5.
Check 1 Replace the FL inverter board with a new one and test the display again. If the
problem still exists, perform Check 2.
Check 2 Replace the FL with a new one and test the display again. If the problem still
exists, perform Check 3.
Check 3 Replace the LCD module with a new one and test the display again. If the
problem still exists, perform Check 4.
Check 4 Replace the display cable with a new one and test the display again. If the
problem still exists, perform Check 5.
Check 5 The I/O board may be damaged. Replace the I/O board with a new one. If the
problem still exists, perform Check 6.
Check 6 The system board may be damaged. Replace the system board with a new one.
650CT
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