Bosch dishwasher has no power

Bosch dishwasher has no power

My friends Bosch dishwasher model Model Number: SHE68M05UC/50 has no power. We checked the power source with a voltmeter and it said 120. Then we follow it up and checked the on and off switch that was ok then we checked the door lock switch and that seemed ok. Then all of a sudden it had power so we unplugged it from the extension cord hooked everything back up and plugged it back in and now there is no power again. We are stumped can anyone help???