How to Fix a Microwave Making Noise – Microwave Repair

How to Fix a Noisy Microwave

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Drive Motor

If an unusual noise is coming from your microwave turntable, the issue may be the drive motor . The microwave uses a motor driven coupler to turn the glass tray in your microwave. The motor should be replaced if it is making a grinding noise. To access the motor, first unplug the microwave. The motor is usually located in the bottom of the microwave, and is held in place by a retaining screw and wires.


If your microwave is making a loud humming or buzzing noise, it may mean the magnetron is not working properly. The magnetron is part of the high voltage circuit that generates heat in the microwave. To access the magnetron, first unplug the microwave, remove the cabinet and discharge the high voltage capacitor. Verify that the mounting bolts are tight and that the high voltage diode is working before concluding that the magnetron needs to be replaced.

Drive Coupler

An unusual noise coming from your microwave may mean there is a problem with the drive coupler, which helps power the glass turning tray. Whether your microwave has a circular or rectangular tray, remove the tray and roller guide to inspect the coupler. You may need to remove the motor from the floor of the microwave before inspecting the coupler on some models. Most couplers have a D-shaped opening where they fit into the motor shaft. Inspect the opening for cracks and wear, which could be causing the unusual noise.

Roller Guide

If an unusual noise is coming from the turn tray in your microwave, the issue could be with the roller guide, which helps the turn tray to rotate without friction. Lift the tray out of your microwave and check the roller guide for signs of damage or wear. Replace the roller guide if it is cracked or worn, and check where it meets the coupler to ensure that it is in place when the microwave is in use. On some models, the unusual noise could be coming from the roller guide wheels, so check those as well.

High Voltage Diode

If your microwave is making an unusual noise that sounds like loud humming, the high voltage diode may be the problem. This part works with the capacitor and magnetron to heat the microwave. Before attempting to access the diode, unplug your microwave, remove the cabinet and discharge the high voltage capacitor to avoid getting an electrical shock. Locate the diode, and check its continuity with a multi-meter. Check the continuity of the diode in the opposite direction as well by reversing the meter leads. The meter should show continuity in one direction for a working high voltage diode, otherwise it should be replaced.

Cooling Fan

An unusual noise when your microwave is on may be coming from the cooling fan. The cooling fan cools the magnetron while the microwave is in use, and is located inside the cabinet. To access it, first unplug the microwave and remove the cabinet. Remove the cover of the fan assembly, and check for any wear or damage to the blades, or any other objects which the blades might be coming in contact with and causing the noise.

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