I have an older Millermatic 200 that has seen light use since it was purchased new. It has always worked flawlessly. It has been connected in the same location for 12 years. The input voltage checks out and no connections appear to be loose. Today when I went to use it the breaker tripped almost instantly. I was getting a welding spark but it was clear the unit was drawing a lot of current the the breaker tripped within 10 seconds. After trying different settings and then disconnecting the output cables entirely it is still drawing current such that it trips the breaker within seconds. I suspect some part of the electronics has let go due to old age. Does anyone have any thoughts as to what the problem might be? 
