I saw your post a few days ago and though of it today when I had a 60 in 1 board get delivered to me. First thing I did was test it in an existing cabinet with a 60 in 1 already in it. No video... but the music started up after a minute or so.
I know you checked .. but my issue was the jumpers... (jumper 2 wasn't on). Once I set jumper 2 to on, and the rest off, it worked.
So did you have any music but no video? or did you have it programmed not to have any music when not playing any games? Do the lights all show it booting and then move to a running state?