Anecdotal evidence only:
- my GF powered itself off like that once after completing calibration. This unit never worked properly…a replacement is on the way. However, after unplugging from the wall for a bit, when I reconnected power, it powered on fine.
- @txsughroue had similar happen to his, and it recovered fine. See the thread linked below.
So I would unplug it, let it sit for a good 5 minutes, then plug it back in. It may be that a slow-reset failsafe tripped in the power supply due to some power glitch.