I am restoring a Funhouse that needed lots of help. I am really close to finishing. I bought a used sound board trying to keep the original sound. Right after startup,it has a loud SCREECH,for about 2 seconds, then sounds good with clear sound. The one lower cabinet speaker is blown. It still has the loud noise without the speaker & all roms removed. All speaker wires test good for continuity. Does anybody have any ideas?