Probe the edge connector at the audio pins with a multimeter and see if you get a voltage. If you do, do a continuity test on your speakers with them unplugged.
I'm not a pro, but I think those are a few easy tests to start. Mv1a is jamma compliant. I'm assuming it passes audio via regular jamma + and - audio pins.
If you fail the first test, you might want to seach about an audio cap that goes on these boards. Maybe it will be clearly visible if burt out.