Still working on this? I've had a bad experience with repairing one of these several years ago (although I finally got it). There's also one of these machines sitting in my parents' garage, and the board from it is on the shelf in my garage. (don't get excited, the board is bad). Anyway, I may be able to help with the connections. SOMEWHERE I have a book on them with a machine schematics, and a partial schematic of the board that I drew myself, although God only knows if I can even find that book. The one that I had trouble with, I struggled with a problem similar to yours for DAYS, and it ended up being a simple 5-minute fix. This has been between 12 & 15 years ago, but I still remember it pretty well. I even labeled that section of the book: "Heliwelder IV, Machine from Hell".