Hitting the limits on the power supply, as far as I know. My best theory, anyway.
I could be wrong, too.
My work machine, a Partner IV, w/CentV, goes flickers, then blacks out, if I push the feedrate up too high while cutting at high rpm. It would come back on, when the feedrate or the rpm were dropped. Fairly consistently.
I've been pondering putting a meter to the power supply when it's under load, but it has not been, well, enough of a bother to get around to it.
Ours did not just stall in place, it tended to keep running the program, just no screen. I think I had it just stop, once.
I was wondering if the draw was causing the power at the 110v power supply to fade out a bit.
It had other issues right now. Trying to get some forward motion on a single-card upgrade that should have been a no-brainer.