PowerPro 256 kicks out on AC tig

[worntorn]

I purchased this unit in 2011. It's always worked perfectly for all functions. A couple of days ago while welding some 1/8" aluminum at 125 amps +-, the torch shut off.
The overcurrent warning light was on, showing green.
After shutting the machine off for an hour or so I turned it back on. The overcurrent light came on with the welder, amber this time.
After a few seconds the overcurrent light went off. The welder worked fine to finish welding up a motorcycle fuel tank I've been building. This is in .063" Al. , so amps were 70+-.
After finishing the .063", I welded some .125" mounts on. The welder cut out again. Turning power off then restarting brings back normal function, except now the welder will cut out in a few seconds at anything over 70 amps.
DC Tig , DC stick and Plasma all work fine to full power.
Is there a thermal cutout specifically for the AC output?
I'm wondering if the thermal cutout is faulty.
I have contacted Everlast Technical support.
They suggested shipping the welder to them for repair. Shipping and repair could easily cost more than the welder is worth, although I do like this unit a lot.
Just realized this should be in the multi-process section.
I'll look for a delete button
Glen