First, make sure that you check the following:
- Your monitor does support sound. PC monitors do not support sound, while TV almost always support sound.
- If you use an HDMI-to-DVI adapter or cable, then you cannot get sound. DVI does not allow audio signals to go though. You should be able to use the analog mini-jack to get audio.
- Make sure your TV is not muted, and that the volume is on high.
- If you have a second HDMI cable, try replacing it. Some very cheap HDMI cables do not work properly.
- Go to "Monitors"
- Go to the details of the monitor with the issue
- Click on the tab "Advanced"
- Activate "overwrite raspberry configuration"
- In the "raspberry configuration file" field, enter ONE the following lines (one should work) :
- Click the "Save" button. After a while, your Raspberry will reboot.