i just bought a syncrowave 200 tig welder used, it has about 34 hours on it. i was welding last night, it was welding great and this morning when i tried to continue welding it wouldnt arc . it would make the hight frequency noise when i hit the pedal, the gas was flowing, and the ground was good but no arc. when i look at the display it said 5 amps with the pedal all the way down and just wouldnt go any higher. any ideas?