Display Troubleshooting - Toshiba Libretto 50CT User Manual

2 Troubleshooting Procedures
2.9

Display Troubleshooting

This section describes how to determine if the display is functioning properly. Start with
Procedure 1 and continue with other procedures as instructed.
Procedure 1: Diagnostic Test Program Execution Check
Procedure 2: Connector Check
Procedure 3: Replacement Check
Procedure 1 Diagnostic Test Program Execution Check
The Display Test program is stored on the Diagnostics Disk. This program checks the display
controller on the system board. Insert the Diagnostics disk into the floppy disk drive, turn on
the computer, and run the test. Refer to Chapter 3, Tests and Diagnostics, for details.
If an error is detected, go to Procedure 3. If an error is not detected, the display is
functioning properly.
Procedure 2 Connector Check
The Display unit has an LCD module, FL, and FL inverter board.
Disassemble the display unit and check the cable connections. Refer to Chapter 4,
Replacement Procedures, for more information about how to disassemble the computer.
If any cable is not connected, firmly reconnect it and repeat Procedures 1 and 2. If the
problem still exists, go to Procedure 4.
Procedure 3 Replacement Check
The FL, FL inverter board, LCD module, LCD flat cable, and system board 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 do
the following checks:
If the FL does not light, go to Check 4.
If characters are not displayed clearly, go to Check 3.
If some screen functions do not operate properly, go to Check 3.
Check 1 Replace the LCD flat cable with a new one and test the display again. If the
problem still exists, go to Check 2.
Libretto 50CT/70CT Maintenance Manual
2.9 Display Troubleshooting
2-25