I recently tried adding a GPIO ribbon extension cable to my setup. I got the red blinking light to indicate low power. I removed the cable and considered it a failed experiment.
I reattached my DAC2 and everything was fine for a while, but I tried using it yesterday and no sound was being output. I right-clicked on the audio tab on Raspeberry Pi OS (icon in top right corner) and I got the message "No audio devices found."
I ran aplay -l and the card was still being detected.
Did I cause damage to the DAC2 HD? If so, is it something that could be fixed by soldering on a new GPIO header, or do I need to buy a new board?