Acer TravelMate P453-M Service Manual page 189

Click Mixer to verify that other audio applications are set to 50 and not muted.

6. Navigate to Start
Speakers are selected as the default audio device (green check mark).
NOTE: NOTE:
If Speakers do not show, right-click on the Playback tab and select Show Disabled
Devices (clear by default).
7. Select Speakers and click Configure to start Speaker Setup. Follow the on-screen prompts
to configure the speakers.
8. Remove any recently installed hardware or software.
9. Restore system and file settings from a known good date using System Restore.
10. If the issue is remains, repeat step 9, selecting an earlier time and date.
11. Reinstall the Operating System.
12. Connect a set of earphones or external speakers. If these function correctly, the internal
speaker or I/O board may be defective. If they do not function correctly, the mother board
may be defective or damaged.
13. If the Issue is still not resolved, refer to
Troubleshooting
 
Control Panel Hardware and Sound

Sound. Confirm that
Online Support Information.
4-11