Forcing HDMI audio

[thedjm]

Re: [SOLVED] Portable retropie device won't output sound from speakers unless hdmi plugged in at startup

Hi,

I've set all the forced /boot/config.txt options to HDMI, but the only thing that seems to work is to raspi-config from the command-line and force HDMI through the Advanced>Audio menu.

The problem is then anytime I reboot, that setting gets lost and I need to rerun raspi-config and re-force HDMI audio again.

Isn't raspi-config just modifying /boot/config.txt? What am I missing? Is something else auto-overriding /boot/config.txt at boot time? What boolean is Advanced>Audio>Force HDMI setting?

Thanks!

[mitu]

Using raspi-config to change the audio output will not write to /boot/config.txt, but will change the ALSA (sound system) settings.
Changing the settings from the raspi-config will invoke

amixer cset numid=3 2

underneath. Try running this command from the command line (exit EmulationStation via the menu or by pressing F4) and see if the settings are kept after a reboot.
If that doesn't work, then add more info about your system, as detailed in https://retropie.org.uk/forum/topic/3/read-this-first.