Troubleshooting Audio

Situation: Audio is not working over HDMI

Possibility 1: The TV/Monitor is not being detected in CEA mode

DMT is only well defined in DVI and DVI can not do audio. Audio only works in CEA modes..

# run to detect if tv/monitor mode 
tvservice -s

# tvservice -m CEA
# tvservice -m DMT

Uncomment the following in /boot/config.txt to force an HDMI mode. It can make audio work in DMT (computer monitor) modes.

NOTE: /boot/config.txt is kinda like the Linux version of BIOS settings

# Force the monitor to HDMI mode so that sound will be sent over HDMI cable

Now reboot for the changes to take effect

sudo reboot