I am getting a crackling noise from the backbox speakers whenever I press the flipper buttons. I am confident that it is not the speakers themselves.

All of the speech and EPROMs are new. I have reset them to make sure they are seated properly.

I am assuming this is a sound board issue. Any ideas on what to check?

Thanks
David

I should also add that it does it sporadically when playing, not just what you press the flippers. I found it odd that it would happen when the flippers were used as I cannot think of a game that uses sound when you flip (except during attract mode).