Makes a loud humming noise while operating

Whirlpool Microwave Buzzing Loudly - ApplianceBlog

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Aug 12, 2011 - 10 posts - ‎2 authors
My Whirlpool MT4155SPS-2 microwave oven has recently started to buzz loudlywhen operated. The sound is getting louder and more frequent ...

Whirlpool making intermittent loud buzzing noise Microwave ...

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Whirlpool microwave ovens making intermittent loud buzzing noise related questions and answers. Ask your ... ...loud buzzing noise and it doesn't heat. i just tried it again and let it run for 1 minute. ... Question about Accuwave Microwave Oven.

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If your microwave buzzes loudly and produces no heat you probably have a defective power .... I have a whirlpool oven range and it's less than a year old. .... Humming sound stops when I open door to remove food, but when door is closed, ...

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follow this test and fix it. God bless you

1. MagnetronIf your microwave is emanating high pitched or growling noises during operation, the magnetron could be going bad. Normally a nearly silent part, the magnetron uses high voltage and induces the frequency required to cook food. Although normally not a safety hazard to operate, this is a sign that the magnetron is failing and will need to be replaced as soon as possible.
   
2. Exhaust fan motorIf your microwave is making a very loud humming noise during operation, it could possibly be the exhaust fan motor. If defective the part will need to be replaced to silence the appliance once more.
   
3. Stirrer motorAnother leading cause of a noisy microwave is an expired stirrer motor. With use this part becomes worn and makes a loud grinding noise, which is usually a leading indicator that the part needs to be replaced. The stirrer is a metal blade that is slowly turned by the motor. This action disperses the microwave energy in a random pattern, which heats the food evenly. If the stirrer motor is determined to be nearing expiration, it should be replaced to halt the grinding noise.
   
4. Turntable motorA very common cause for a noisy microwave is a worn out turntable motor. This is a relatively easy repair and will put an end to the noise once replaced.
   

make this test and fix it. God bless you

1. MagnetronIf your microwave is emanating high pitched or growling noises during operation, the magnetron could be going bad. Normally a nearly silent part, the magnetron uses high voltage and induces the frequency required to cook food. Although normally not a safety hazard to operate, this is a sign that the magnetron is failing and will need to be replaced as soon as possible.
   
2. Exhaust fan motorIf your microwave is making a very loud humming noise during operation, it could possibly be the exhaust fan motor. If defective the part will need to be replaced to silence the appliance once more.
   
3. Stirrer motorAnother leading cause of a noisy microwave is an expired stirrer motor. With use this part becomes worn and makes a loud grinding noise, which is usually a leading indicator that the part needs to be replaced. The stirrer is a metal blade that is slowly turned by the motor. This action disperses the microwave energy in a random pattern, which heats the food evenly. If the stirrer motor is determined to be nearing expiration, it should be replaced to halt the grinding noise.
   
4. Turntable motorA very common cause for a noisy microwave is a worn out turntable motor. This is a relatively easy repair and will put an end to the noise once replaced.
   

make this test and fix it. God bless you

1. MagnetronIf your microwave is emanating high pitched or growling noises during operation, the magnetron could be going bad. Normally a nearly silent part, the magnetron uses high voltage and induces the frequency required to cook food. Although normally not a safety hazard to operate, this is a sign that the magnetron is failing and will need to be replaced as soon as possible.
   
2. Exhaust fan motorIf your microwave is making a very loud humming noise during operation, it could possibly be the exhaust fan motor. If defective the part will need to be replaced to silence the appliance once more.
   
3. Stirrer motorAnother leading cause of a noisy microwave is an expired stirrer motor. With use this part becomes worn and makes a loud grinding noise, which is usually a leading indicator that the part needs to be replaced. The stirrer is a metal blade that is slowly turned by the motor. This action disperses the microwave energy in a random pattern, which heats the food evenly. If the stirrer motor is determined to be nearing expiration, it should be replaced to halt the grinding noise.
   
4. Turntable motorA very common cause for a noisy microwave is a worn out turntable motor. This is a relatively easy repair and will put an end to the noise once replaced.
   

Unit uses a Magnetron and likely a power board called an inverter to run it. Someone would have to open the unit in a way where they might pinpoint where the sound is coming from and then take action--does not of course sound normal or good to me.

Disconnect the HV transformer leads from the magnetron and the capacitor. Make sure none of the wires are touching the chasis or other parts. If the loud humming sound is still present, it is the High Voltage transformer making the noise. If the noise goes away, it is the High Voltage Capacitor going bad.

*MAKE SURE TO UNPLUG UNIT BEFORE TOUCHING ANY OF THE HIGH VOLTAGE LEADS! ALSO, DISCHARGE THE CAPACITOR BY SHORTING THE TWO SIDES AGAINST EACH OTHER!

The magnetron has failed or the high voltage transformer is the problem, either way! it is very expensive to replace, cheaper to buy new.

I have the same model ending in 003, and it has made this noise for most of its life of several years now. Every now and again it runs quietly.

My theory is the cooling fan (not the hood fan) is making noise. The problem began within the first year of operation, and up till now everything is in good working order otherwise. There is no odor of failing parts.

My installation book has no electrical circuit diagrams, and I came upon your question when searching the topic.

shorted HV diode,or shorted wiring in transformer

If it making a louder than normal humming or grunting sound when operating, than it's a sure bet it's the MAG.