NBA JAM TE Sound Problem...

I have a TMNT 4 player cabinet that I installed NBA JAM TE in last night. I double and triple checked the harnesses (Power plugs and ribbon cable, red line on the 1-pin on main pcb and sound card.) and the volume pot is soldered directly to the sound board.(Pins 2 & 4 at P5...) What I'm getting is a crackling/static sound through the speaker. When I run the sound diagnostic, the board detects an IRQ. I can hear the sound effects faint in the background when playing the game. If I turn up the volume pot the crackling/static gets louder with volume so it seems to be doing it's job.

Any help/suggestions are much appreciated!

-Matt