User Guide


Product System (PS)
Subject:
C4-425 Trouble Shooting Guide
Part No.:
99.K4501.000
Rev.: 0
Doc. No.
99.K4501.000-C4-425-001
Project Code:
99.K4501.001
Component Part.
No.:
NA
Page 23 of 35
Model Name:
DHS5
Form No: BQY0-0B-003-32(031205)
23
1.6 Keyboard
To check if the computer’s keyboard is defective or malfunctioning, follow the troubleshooting
procedures below as instructed.
Procedure 1 Test Program Check
Procedure 2 Connector Check and Replacement Check
Procedure 1 Test Program Check
Execute the Keyboard test available as part of the maintenance test program. See Diagnostic user guide
for information on how to perform the test.
If an error is detected in the test, go to Procedure 2. If no error is detected, the keyboard itself is normal.
Procedure 2 Connector Check and Replacement Check
The keyboard or system board may be disconnected or faulty. Disassemble the computer following the
steps described in Tear Down guide and perform the following checks:
Check 1 Make sure the keyboard cable has been firmly connected to the system board.
Keyboard
System board
CPU
If the cable is loose or off, reconnect it firmly and return to Procedure 2. If there is still an
error, perform Check 2.
Check 2 The keyboard may be faulty. Replace it with a new one following the instructions in Tear
down guide. If the problem persists, perform Check 3.
Check 3 The System board may be faulty. Replace it with a new one following the instructions in
Tear Down guide.