I have an Astro City and an MK3 board (sound does not work on my cabinet). I've heard that the Astro power supply has a very weak -5v output, which seems to be the case with my cab (I am pretty sure the -5v is properly wired, but much less than -5v is actually supplied to the board).
So, check the JAMMA harness and the cabinet PSU to see if the -5v is wired and, if it is, measure the power being supplied using a multimeter.