Raspberry pi 0 no audio through hdmi

Hello all! I am stumped! I have sucessfully run raspian, retropie and have sound through the hdmi. I decided to give the new version of riscos a drive and have almost every thing working except sound. I have put the current version rom file and firmware files also set the hdmi_drive=2 flag in the config.txt. volume turned up and tested with all 5 ports on my tv and still no sound. Clues? Ideas? Please help me. Also my tv is a brand new vizio and i also use it with my pc and sound works there too.

Did you ever get this working? I felt a bit bad that I couldn’t help. My Zero is plugged into my PC’s monitor via a HDMI to DVI adaptor. It’s part of the reason I went to the trouble of building the PWM out and working out how to use it. My Zero is now a dedicated RISC OS machine.

The only things I can think of are increasing the HDMI drive level a little or updating the Pi firmware again. Can’t speak for HDMI audio but PWM sound went really wonky for about a week or two around the end of September. It’s been fixed now.

As far as I know all the audio generation is done by VideoCore, not RISC OS, so it’s possible there is something a bit off with the firmware. Either that or the real pain to verify on a Zero possibility that RISC OS is just failing to output sound.