Make sure the plug is inserted securely into the wall outlet if the display does not work or the oven fails to operate. Check the electrical panel box for any blown fuses or tripped breakers. Replace blown fuses with new ones of the same amperage or reset breakers as necessary.
Check to see there is no packing material stuck in the oven door if the display comes on but the power does not. Close the door securely. Press the STOP/CLEAR button twice, then reset all your programmed cooking instructions.
Remove the plug from the wall socket for 10 minutes if there has been a power outage. The time indicator will read "8888." Plug the unit back into the wall socket and reset the clock and cooking instructions.
Make sure the unit is on its own 20-amp circuit line if food is cooking too slowly. Other appliances on the same line can draw power from the microwave and cause the voltage to drop.
Clean the interior turntable and roller ring, as well as the floor of the oven if the unit is making a noise or is sticking. Check that the turntable and ring are correctly positioned.