A customer called with some sketchy info on her T652 powering itself off. She turned it back on and it operated for a few minutes and then shut down. She did this 3 or 4 times.

Then she let the printer stay shut down for 1/2 hour sna turned it on - everythings is fine.

What can be done to diagnose the problem properly if this reoccurs?

suspicion would be that it is a problem with either the fuser, power supply or contrl board.