The part(s) or condition(s) listed below for the symptom Microwave is loud or noisy are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.
To determine if the fan motor is defective, remove the fan motor from the microwave and try turning the fan blades by hand. If the blades do not turn freely, replace the fan motor. If the fan blades do turn freely, use a multimeter to test the motor for incoming power and for continuity. If the motor has power but won’t run, replace it. If the motor does not have continuity, replace it.