Microwave makes loud electric sound when I turn it on, still works

Question

Microwave Oven

Repair guides and troubleshooting information for microwave ovens.

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Brandon @gyarados

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crwdns2931729:0crwdne2931729:0: Mha 15, 2018

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Microwave makes loud electric sound when I turn it on, still works

When I started cooking with my microwave (Whirlpool model), I heard a loud electric popping sound but it continued to run and cooked my food just fine. I thought it might be a one-off occurrence, but it happened again later. I suspect it has something to do with the capacitor discharging itself when the microwave turns on, but when I opened it up I didn’t see any burn marks or other indications of what might be causing it. Any ideas?

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Same problem here. Only one loud crack coming from the back of the unit as soon as i press start then nothing and cooks fine. Has anyone git an answer yet?

crwdns2934271:0Dzi 1, 2020crwdnd2934271:0 Cameron crwdne2934271:0

Yep, it was a shorted high voltage diode (see chosen solution). Replacements can be purchased for $15-20. Be sure you discharge the capacitor first, either by leaving the microwave unplugged for a few days or connecting the terminals with an insulated screwdriver (see YouTube).

crwdns2934271:0Dzi 1, 2020crwdnd2934271:0 Brandon crwdne2934271:0

Thankyou brandon

crwdns2934271:0Dzi 1, 2020crwdnd2934271:0 Cameron crwdne2934271:0

I had the same problem with my Whirlpool over stove microwave. I replaced the diode and it's still doign the same thing...a lound pop/crack when forst started in th emorings. Other than that it works fine. So now off to buy a new microwave

crwdns2934271:0Mha 19, 2021crwdnd2934271:0 Greg crwdne2934271:0

It happens when humidity is over 70%, whether from humid day’s air or too much boiling on stove underneath. Is it dangerous? Can it be fixed? Why does it make this loud snap?

crwdns2934271:0Mha 30, 2021crwdnd2934271:0 Tom Riordan crwdne2934271:0

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Brandon @gyarados

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crwdns2931729:0crwdne2931729:0: Kul 9, 2020

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The problem turned out to be a fried high voltage diode. The design of this microwave is such that greasy air is drawn through the innards when the venting fan is used, causing a buildup of oily crud on the electronic components inside. The diode was also touching another wire, which might have caused it to short. In any case, you can order and replace the diode easily and cheaply. Be sure to unplug the microwave and let it sit for a few days to make sure the capacitor is discharged first.

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I have had three microwave and all three have done the same thing and blue fire shoots out the back

crwdns2934271:0Huk 2, 2020crwdnd2934271:0 Edward Angel crwdne2934271:0

@gyarados, did the popping occur on the first use of the day or each time the unit was used? I’m having this issue with a 2 year old Whirlpool unit. I don’t have capacity to fix and trying to determine should I replace or have service rep come fix it and than maybe having to do the same thing 2 years down the road.

crwdns2934271:0Maw 21, 2021crwdnd2934271:0 Jacqueline Hightower crwdne2934271:0

Mine makes a popping noise while in use but it’s not the food and it’s not arcing

crwdns2934271:0Sun 25, 2023crwdnd2934271:0 bonniejmuir crwdne2934271:0

“WHEN IN DOUBT, THROW IT OUT”

microwave shelf life? 9 years

I just read the info on the door. My microwave is 15 years old. It’s on the wall. It lasted only because my house was a vacation house that was visited about 2-4 days per year!!

I guess Thanksgiving Day sale is coming soon.

crwdns2934271:0Nhl 21, 2023crwdnd2934271:0 Lorraine crwdne2934271:0

Oh and please 🙏🏼 do not try to fix it. You can’t. You even have to throw it in a separate place at the dump. So if it makes loud starling sounds like mine don’t try to fix it. It’s a microwave and it is meant to be thrown away even if there is a problem with the door seal because microwaves can escape and harm you. They can cause an explosion, fire, disfigured body, blindness and even death. ☠️

crwdns2934271:0Nhl 21, 2023crwdnd2934271:0 Lorraine crwdne2934271:0

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Same problem here. Only one loud crack coming from the back of the unit as soon as i press start then nothing and cooks fine. Has anyone git an answer yet? — Cameron
Yep, it was a shorted high voltage diode (see chosen solution). Replacements can be purchased for $15-20. Be sure you discharge the capacitor first, either by leaving the microwave unplugged for a few days or connecting the terminals with an insulated screwdriver (see YouTube). — Brandon
I had the same problem with my Whirlpool over stove microwave. I replaced the diode and it's still doign the same thing...a lound pop/crack when forst started in th emorings. Other than that it works fine. So now off to buy a new microwave — Greg
It happens when humidity is over 70%, whether from humid day’s air or too much boiling on stove underneath. Is it dangerous? Can it be fixed? Why does it make this loud snap? — Tom Riordan
I have had three microwave and all three have done the same thing and blue fire shoots out the back — Edward Angel
@gyarados, did the popping occur on the first use of the day or each time the unit was used? I’m having this issue with a 2 year old Whirlpool unit. I don’t have capacity to fix and trying to determine should I replace or have service rep come fix it and than maybe having to do the same thing 2 years down the road. — Jacqueline Hightower
Mine makes a popping noise while in use but it’s not the food and it’s not arcing — bonniejmuir
“WHEN IN DOUBT, THROW IT OUT”

microwave shelf life? 9 years

I just read the info on the door. My microwave is 15 years old. It’s on the wall. It lasted only because my house was a vacation house that was visited about 2-4 days per year!!

I guess Thanksgiving Day sale is coming soon. — Lorraine
Oh and please 🙏🏼 do not try to fix it. You can’t. You even have to throw it in a separate place at the dump. So if it makes loud starling sounds like mine don’t try to fix it. It’s a microwave and it is meant to be thrown away even if there is a problem with the door seal because microwaves can escape and harm you. They can cause an explosion, fire, disfigured body, blindness and even death. ☠️ — Lorraine

score 2 · Answer 1 · 2018-08-15T19:39:17-07:00

mayer @mayer

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MacHale Enterprises

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crwdns2931729:0crwdne2931729:0: Mha 15, 2018

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Cause 1

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 can store a lethal amount of electricity in its high voltage capacitor, even after the microwave oven has been unplugged. Due to the high running voltage and the potential for electric shock, it is extremely dangerous to replace the electronic components in a microwave. Only a licensed technician should replace the magnetron.)

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I don't think it's the magnetron, as the sound was a sharp pop when the microwave starts cooking, not a continuous hum or anything.

crwdns2934271:0Mha 15, 2018crwdnd2934271:0 Brandon crwdne2934271:0

Hello, I have the same problem with my Bosch microwave. Have you figured out the problem yet?

crwdns2934271:0Yan 8, 2019crwdnd2934271:0 koray_palazoglu crwdne2934271:0

Hi I have a Panasonic Genius microwave oven and same symptoms. When start to cook within 5 seconds 1 or 2 loud electrical pop sounds occurs. The electrical pop sound is loud enough to scare anyone who uses the microwave oven. In my case it does not occur consistently? The foods cook normally.

crwdns2934271:0Huk 21, 2019crwdnd2934271:0 Nick Nishino crwdne2934271:0

Same issue here a friend suggested it's a result of cockroaches but I don't know how true that is.

crwdns2934271:0N'w 11, 2019crwdnd2934271:0 daniel waweru crwdne2934271:0

Same issue here...it scares the !&&* out of me...sounds like a loud cap pop gun if I had to try to describe it but it's only when it's first starts. Cooks normally... definitely sounds electricial and is so loud.just one quick pop

crwdns2934271:0N'w 21, 2019crwdnd2934271:0 Sara Johnson crwdne2934271:0

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