The laser printer here at my office just had a series of jams, one of which tripped the “Call a service Tech” flag on the darned thing. Rather than calling the tech to reset it (I managed to clear the paper problem myself), you can simply enter this code on the control panel:
Then Press Execute, then Tap Yes, then hit the B/W Copy button, then hit the reset button.
P = Program (#)
C = Clear
Problem solved, no maintenance fees!