Toshiba Satellite A500D Series Maintenance Manual page 54

Procedure 1 External keyboard check
Connect a USB keyboard to one of the computer's USB ports, and then boot the computer.
The computer automatically detects the external keyboard.
If the external keyboard works correctly, the internal keyboard or its connections may be
faulty. Go to Procedure 2.
If the external keyboard appears to have the same problem as the internal keyboard, the
system board may be having some problem. Replace it with a new one and following the
instructions in Chapter 4.
Procedure 2 Diagnostic check
test and Diagnostics
Run the
Tests and Diagnostics
Refer to Chapter 3,
If an error is located, go to Procedure 3. If an error does not occur, the keyboard is
functioning ok.
Procedure 3 Connector and replacement check
The keyboard and/or system board may be disconnected or damaged. Disassemble the
computer following the steps described in Chapter 4, Replacement Procedures and perform
the following checks.
Check 1 Make sure the keyboard cable is firmly connected to the system board.
If the connection is loose, reconnect firmly and repeat Procedure 2. If there is still
an error, go to Check 2.
Check 2 The keyboard may be damaged. Replace it with a new one following the
instructions in Chapter 4.
If the problem still exists, perform Check 3.
Check 3 The system board may be damaged. Replace it with a new one following the
instructions in Chapter 4.
Satellite A500D/Satellite A505D/Satellite A507D/Satellite Pro Series Maintenance Manual
Program, which will automatically execute the Keyboard Test.
for more information on how to run the program.
2 Troubleshooting Procedures
18