I had a pf light socket short that was blowing the fuse, and I had a circuit breaker that I was using in place of the fuse while troubleshooting. The breaker took a little longer to blow than the actual fuse did, so I dimmed the room lights, turned on the machine, and in the 3 seconds or so before the breaker blew, I could actually see the glow where the short was happening. Might be worth a try...