Toshiba M645-S4080 Maintenance Manual page 56

2 Troubleshooting Procedures
To determine if the computer's built-in speakers are functioning properly, perform the
following procedures. Figure 2-8 outlines the process. First adjust the speaker volume to an
appropriate level. Start with Procedure 1 and continue as instructed.
Procedure 1: Audio source test
Procedure 2: Earphone test
Procedure 3: Connection check
Procedure 4: Replacement check
Procedure 1
Try different audio sources (e.g. an audio CD and digital music file) to determine whether the
fault is in the speaker system or not. If not all sources have sound problem, the problem is in
the source devices. If all have the same problem, continue with Procedure 2.
Procedure 2
Connect a set if earphones or external speakers. If these function correctly, go to Procedure 3.
If they do not function correctly, the system board may be defective or damaged. Replace it
with a new one.
Procedure 3
Disassemble the computer following the steps described in Chapter 4, Replacement
Procedures and make sure the speaker cable is firmly connected to the audio board. If the
stereo speakers are still not functioning properly, go to Procedure 4.
Procedure 4
If the stereo speakers don't sound properly, the stereo speakers may be defective or damaged.
Replace them with new ones. If the stereo speakers still do not work properly, try replacing in
turn the audio board and system board.
Satellite/Satellite Pro M600/M640/M645/M647 Series/Dynabook TX/AX Series Maintenance Manual
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Audio source test
Earphone test
Connection check
Replacement check
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