Miller 375 only has pilot arc

[Cobr96]

Hello everyone, I have a spectrum 375, bought new several years ago, probably had less than an hour of actual use but it might be 10 years old, last time I used it no problems, it's been sitting now about 5 years. So today I plug it in, connect the air and pull the trigger and it only puts out a pilot arc for a second the power light turns off for a second then back on and it will do the same again. No warning lights are on. All cup parts are new, air supply is good, ground clamp is good. Has continuity all the way to the circuit board, running on 110v, any ideas? I am wondering if the two big capacitors have come bad? They aren't swollen or leaking.
thanks in advance