Toshiba T4400SXC Maintenance Manual page 32

2.7 Keyboard Troubleshooting Steps
To detennine if the T4400SXC's keyboard is functioning properly, perfonn the following
steps. Start with Step 1 and continue with the other steps as required.
Step 1:
Test Program Checklist
Step 2:
Connector and Replacement Checklist
Step 1 Test Program Checklist
Execute the keyboard portion of the Diagnostic Test program. Refer to part 3, Test and
Diagnostics for more information on how to perform the test program.
If an error occurs, perform Step 2. If an error does not occur, the keyboard is functioning
properly.
Step 2 Connector and Replacement Checklist
The keyboard is connected to the system board by a 19-pin flat cable. This cable can become
disconnected or damaged. Disassemble the T4400SXC as described in part 4, Replacement
Procedures and follow the checks below:
Check 1 Make sure the keyboard cable is not damaged and is connected to the system
board.
I
Keyboard cable 1-1-----lL-_S_y_st_e_m_bo_a_rd_p_J_1_
4
----J
If this cable is damaged, replace it with a new one or connect it if it is
disconnected. Perform step 1 again. If the keyboard is still not functioning
properly, perfonn check 2.
Check 2 The keyboard controller on the system board may be damaged. Replace the
system board with a new one. Refer to part 4, Replacement Procedures for more
information about how to replace the system board.
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