are you using the correct cable plugged into the
correct place?
this is usually the biggest cause.
sound was mono, and you need the proper wiring, and your tv/etc may
only accept
mono sound on a specific input
I think I'm using the correct cable. The one I'm using for audio
connects to pin 3 of the A/V DIN connector. I'm plugging it into a TV
that only accepts a mono input and I've verified that the TV sound
works correctly by plugging it into an Atari 800xl.