I got a couple of welders from a friend who has a construction business and was buying new gear in exchange for firewood. One works, but the 250g (serial #JK691415 750 hrs) starts and runs fine but won't weld and the plugs don't have any power. I took the hood off and if I take a pair of jumper cables and touch them to the field capacitor the AC outlets (and presumably the welder) start to work. I don't have a service manual but was wondering if anyone had any ideas what might be wrong based on this behavior. I don't need two welders and would probably sell the 250g if I can get it working. Any thoughts?