Your original problem was likely an easy one. Those pots on your sound board are notorious for failing. You also have a lot of 40 year old capacitors that probably need replaced on the sound card. Replacing those items should have had you fixed up. At this point something has been fried. I would recommend sending in the board for repair since you're new to the hobby and tracking down multiple problems is a pain at times. I recommend the "Coin Op Cauldron".