Pretty sure the previous owner of my 500A cooked the power trans. I have replaced all the electrolytics in the unit, and it still is popping fuses. It had a 30 amp fuse in it when it came to me and the fuse was blown. when I remove the load from the transformer (on the high voltage secondary) it turns on and the lights light up. My output transformers show no shorts. Given the smell of the unit when I got it I am going to have to say that it cooked the power trans. Everything else that it could be has been changed. Anyone got a speare? I have barterables...