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HomeRepair HelpUniversal Microwave RepairUniversal Microwave is loud or noisy Repair
Universal Microwave is loud or noisy
A microwave making loud noise, grinding noise, buzzing noise, or unusual fan noise usually has a worn or failing motor. Start with the fan motor, whose bearings can cause rumbling or squealing while the microwave runs. Next, check the magnetron if the noise is a high-pitched sound, growl, or loud hum. A defective high-voltage diode can also make the magnetron noisy, so test the diode before replacing the magnetron. If the sound comes from the vent area, inspect the exhaust fan motor and verify that its blades turn freely, the motor receives power, and it has continuity. A worn glass tray support can make noise as the rollers move beneath the turntable, while a failing stirrer motor may produce grinding as its internal gears wear. Is a noisy microwave dangerous? Do not open the cabinet unless you know proper microwave safety procedures. The high-voltage capacitor can store a lethal charge even after the microwave is unplugged and must be properly discharged before interior work. Magnetron, high-voltage diode, and other high-voltage repairs may require a qualified technician. Enter your model number to find the exact replacement part for your Universal microwave.
01 - Universal Microwave Fan Motor
The fan motor bearings can wear out causing a rumbling or squealing noise. If the fan motor is making noise when its running it will need to be replaced.
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02 - Universal Microwave Magnetron
The magnetron uses high voltage, high current DC power to generate the microwave frequency that cooks the food. Under normal circumstances, the magnetron emits a low hum. However, if the magnetron is damaged or nearly burned out, it may begin emitting high-pitched sounds or growling noises. If the magnetron is noisy, this indicates that the magnetron is nearing the end of its life or might be defective. A defective high-voltage diode can also cause the magnetron to be loud. Before replacing the magnetron, first test the high voltage diode. If the diode is not defective, replace the magnetron. (Warning: The microwave oven c...
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03 - Universal Microwave Diode
The diode converts the AC power output of the transformer to DC, doubling the voltage to nearly 5,000 volts. This high voltage powers the magnetron to heat the food. A failing diode can be responsible for a noisy magnetron. When the diode fails, it is often visibly burned out. Inspect the diode and if the diode is burned out, replace it. If inspecting the diode proves inconclusive, test it with a multimeter that uses a 9-volt battery or put a 9-volt battery in series with the diode. When the leads are reversed, the diode should only have continuity in one direction.
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04 - Universal Microwave Exhaust Fan Motor
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.
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05 - Universal Microwave Glass Tray Support
The microwave glass tray support is the component that sits under the glass turntable tray to support the tray as it rotates. Over time, the small rollers on the support can wear out and start making a noise as the tray turns. If you've determined the glass tray support is the source of the noise, the part should be replaced with a new one.
Highly Likely
06 - Universal Microwave Stirrer Motor
The stirrer is a metal blade which slowly rotates inside in the microwave. As the stirrer turns, it deflects the microwave energy randomly throughout the microwave. As the stirrer motor wears down, it begins to make grinding noises. To determine if the stirrer motor is worn out, check to see if voltage is getting to the motor. If the motor has the proper voltage, but is noisy or won’t turn, replace it. (Note: Proper voltage can be determined by reading the label on the motor. Because the stirrer motor is a geared motor, the shaft will not spin freely.)
Highly Likely
Frequently Asked Questions
Why is my Universal microwave making a loud or noisy sound?
Can a bad magnetron or high-voltage diode make a microwave hum loudly?
How do I test a noisy Universal microwave fan or exhaust fan motor?
Why does my microwave make a grinding noise when the turntable spins?
How do I identify the correct replacement part for my noisy microwave?
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