Procedure 5 Replacement Check - Toshiba T4500 User Manual

If any of these cables are not connected, firmly reconnect them and repeat Procedures 1 and 2. If
the problem still exists, perform Procedure 5.
Procedure 5 Replacement Check
The FL or FL unit, FL inverter board, LCD module, LED board, and System PCB are connected to
the display circuits. Any of these components may be damaged. Refer to Chapter 4, Replacement
Procedures, for instructions on how to disassemble the computer, and then perform the following
checks:
If the FL or FL unit 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 or FL unit remains lit when the display is closed, perform Check 4.
Check 1: Replace the FL (T4500 or T4600) or FL unit (T4500C or T4600C) with a new one and
test the display again. If the problem still exists, perform Check 2.
Check 2: Replace the FL inverter board with a new one and test the display again. If the prob-
lem 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 6.
Check 4: Replace the display switch with a new one and test the display again. If the problem
still exists, perform Check 5.
Check 5: Replace the LED board with a new one and test the display again. If the problem still
exists, perform Check 6.
Check 6: Replace the display cable with a new one and test the display again. If the problem
still exists, perform Check 7.
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