Is a buzzing microwave dangerous? An odd buzzing noise can be frightening when microwaving your meal, but it’s a common problem many people experience. A buzzing sound is an excellent way to tell if it’s worn out or broken. Radiation from the microwave comes out of the magnetron tube, which heats the food and doesn’t make any noise.

Have you noticed that your microwave has been producing unusual noises lately and are unsure whether this is a dangerous situation or not? You may learn more about the buzzing sounds in this article. Please continue reading.

Is A Buzzing Microwave Dangerous? 

If your microwave starts producing strange noises, you shouldn’t be concerned about using it. 

Microwaves are used in various applications, including communications, radar, and, most notably, cooking.

We quickly become accustomed to the simplicity of simply reheating leftovers in the microwave for a quick meal replacement. However, suppose your microwave begins to make a peculiar clicking noise. In that case, this can be upsetting to hear—a prevalent condition with many potential causes.

Is A Buzzing Microwave Dangerous image

Microwave ovens are one of the most frequently used appliances in the house. Because of the high use volume, if your microwave makes weird noises, it is most likely because a component must be replaced. 

Consider whether turning the microwave off and on at the power source or cleaning the microwave can alleviate the noise before investing in new parts and components.

Finding out what is causing the noise your microwave is making and where it is coming from will assist you in determining the problem.

A grinding or clicking sound inside the microwave indicates that the stirrer motor is malfunctioning. In contrast, a grinding or clicking sound from the microwave base suggests that the turntable is malfunctioning.

A high pitch or loud hum suggests a problem with the magnetron or diode. In contrast, a rattling or buzzing sound coming from the rear of the microwave indicates a problem with the cooling fan.

What Is The Source Of The Buzzing Sound Coming From My Microwave?

From my microwave, the buzzing sound is coming from a variety of directions:

1. A Defective Magnetron

Magnetrons are responsible for producing high-frequency electromagnetic waves used to heat the food in a microwave oven. 

When you use your microwave on a low setting, you will frequently hear the magnetron switching on and off to lower the microwave frequencies. At the same time, the food is being cooked in the microwave

Suppose your microwave’s noise sounds similar to the magnetron but louder. In that case, a malfunctioning magnetron (or diode – see below) is likely the source of trouble.

Additionally, a defective magnetron can produce an obnoxious high-pitched sound, which signals that the magnetron tube is degrading due to its age and extensive use.

You can narrow down the possibility of a magnetron problem by using the microwave on a low setting and seeing whether the microwave noise decreases or stops as the magnetron turns on and off while the microwave is on the low setting while cooking.

 It is also possible that an issue with the magnetron is causing the burning odor.

2. Diode With A Defect

The diode, the magnetron, and the capacitor are all components of the high-voltage circuit. 

The high voltage is required to power the magnetron, produced during the conversion from alternating current to direct current.

 A loud buzzing sound often characterizes a defective diode.

3. Failure Of The Cooling Fan

The cooling fan may malfunction, another source of microwave noise. Occasionally, the cooling fan will become dislodged, or debris will become entangled. 

If the fan is clipping against another part of the microwave, or if it is making an audible rattling sound, this could be the cause.

The cooling fan motor can also become worn over time and may require replacement. When the microwave is regularly operating, you should be able to hear the cooling fan running in the background. 

On the other hand, if the noise becomes louder or the microwave begins to make a buzzing noise, typically heard from the rear of the microwave, this suggests a problem with the cooling fan motor.

4. A Faulty Turntable Motor

The turntable motor is another source of microwave noise. A malfunctioning turntable motor is generally accompanied by a clicking or grinding sound.

5. The Stirrer Motor

The stirrer motor drives a metal blade that deflects microwave radiation across the microwave. The stirrer ensures that food heated in the microwave is cooked evenly. A defective stirrer motor will often generate a grinding sound as it strives to keep up with the speed of the stirrer.

How To Fix A Noisy Microwave?

Repairing more complicated problems with a microwave should be left to a qualified microwave technician to avoid the risk of electrocution.

  1. Failure Of The Magnetron

For further testing, operate the microwave on a low setting and check if you can hear the magnetron turn on and off while cooking at the low setting to see if the microwave noise decreases or ceases. 

The magnetron may potentially be malfunctioning if it emits a noxious odor.

Diagnose and repair a malfunctioning magnetron by following these steps:

  • Make sure the microwave is disconnected from the power source before proceeding.
  • Magnetrons can be accessed by removing the top microwave cover.
  • Check for magnetron continuity with a multimeter. One ohm or less should be the limit for each test.
  •  Removing and replacing the magnetron is necessary if it is faulty.
  •   When gaining access to the magnetron, use extreme caution.
  1.  Diode With A Defect

Diodes can be fixed by following these steps:

  • Ensure the microwave is not connected to any power sources before using it.
  • The diode can be accessed by removing the top microwave cover.
  • Capacitors need to be depleted.
  • Check the resistance of the diode with a multimeter. A healthy diode can measure between 50,000 and 200,000 ohms, depending on the brand.
  • By reversing the meter leads, you can check for continuity in the other way. Continuity should be limited to one way only.
  • It is necessary to replace the diode if it is defective.
  • When handling the diode, be careful.
  1. Failure Of The Cooling Fan

Removing other microwave components may be necessary to access the cooling fan. Discharging the capacitor should be done with prudence.

To identify and repair a malfunctioning cooling fan, follow these steps:

  • Remove the microwave’s power cord from the wall outlet.
  • Capacitors need to be depleted.
  • Remove any items obstructing the fan, if necessary.
  • Check to verify if the fan can move freely. Fan motor replacement may be necessary if it is not spinning freely despite the absence of any obstructions.
  • Check for continuity using a multimeter in the cooling fan motor.

      . Depending on the model, a functional cooling fan motor should have a resistance of 280 ohms or less.

  • A faulty fan motor should be replaced.
  1.  A Faulty Turntable Motor

The microwave enclosure will need to be removed if it cannot be accessed from underneath.

To diagnose and repair a damaged turntable motor, follow the steps outlined below:

  • Remove the microwave’s power cord from the wall outlet.
  • Remove the turntable motor panel by unscrewing it.
  •  check the continuity of the turntable motor’s power supply using a multimeter,
  • . It will be necessary to replace it if there is no continuity of operation.
  1.  The Stirrer Motor

To diagnose and repair a malfunctioning stirrer motor, follow the methods outlined below:

  • Remove the microwave’s power cord from the wall.
  • To reach the stirrer motor, you must first enter the microwave chamber and climb above the turntable plate.
  • Remove the cap from the stirrer motor.
  • Check that the stirrer blade has not come free or been damaged.

 You may be able to detach the stirrer motor and operate the microwave to test if the noise continues even with the stirrer motor disconnected.

If the stirrer motor has been damaged, it should be replaced.

What Is The Cost Of A Magnetron And A Diode In A Microwave Oven?

The Price of a Magnetron:

Replacement of a microwave magnetron is expensive.

The cost of replacing a microwave magnetron ranges from $100 to $200. This includes a part price ranging from $50 to $100 and labor charges ranging from $50 to $100.

A magnetron is the fundamental component of the appliance that generates heat for its operation. This section is responsible for the generation of microwave energy.

New magnetrons range in price from $50 to $100. If you’re in the market for one, ensure you get the proper one. It is specific to the brand and model of the microwave, as are most microwave replacement components.

The price of a microwave diode:

Microwave diodes range in price from $5 to $25, and replacement costs range from $50 to $100. You need to replace the magnetron with the possibility of a new diode being included in the package. Package.

Microwave signals are created, received, and switched using diodes, which operate as semiconductors. Over time, it can become worn out, resulting in sparks, loud buzzing, or poor room heating.

Is It Possible To Determine What Causes A Magnetron To Fail In A Microwave?

When the microwave is turned on, and the container is empty, the magnetron gets damaged and eventually burns out.’

 It is impossible to restore a burned magnetron and must be replaced. Other possible causes of this problem include faulty diodes, capacitor burn, a malfunctioning door switch, and a failed transformer.

It doesn’t matter what triggers a breakdown; there are ten reasons why it happens.

  1. Element damage can be caused by rough handling during shipping or installation and misuse in use.

    When the cathode or filament (stem) mishandles the anode jacket and punctures the vacuum seals, the filament becomes misaligned due to improper voltage and current settings, and so on (air and water).
  1.   In most cases, the filament or heater has little likelihood of success. It was breaking before the end of its life cycle. 

As a result, broken rejections are often blamed on vibration or shock. In direct-heated cathodes, thoriated-tungsten wire is used. Carburization, a process that involves treating the surfaces of these components to improve their electron emission, is used to do just that.

 A manufacturer must take special care when packaging and shipping a tube because of its low mechanical strength. Reusing original packaging materials for a reshipment is essential to handling magnetrons properly.

 Falling, impact, etc., should not be handled to cause a sharp shock.

 To heat the cathode, a large amount of current must flow through the filaments. If the current load has poor connections, it can be expected to malfunction. 

Temperatures rise due to poor mechanical contact in wiring, which accelerates the oxidation of the contact points on the board. If the heater filament does not light up during operation, it is important to check the connections, which are frequently mistaken for broken ones.

  1.  It is important to note that both the cathode and the MW antenna of the tube are made of ceramic. The heater’s thermal radiation raises the cathode stem’s temperature to dangerous levels. 

Because of this, some types of magnetrons specify the maximum temperature of the stem and the lead wires in the specifications, and special care must be taken to cool those parts. Ceramic parts can be damaged by an increase in temperature that is unexpected.

It’s fine for a medium-wave antenna to get a little hot when it’s emitting MW radiation and operating normally. The ceramic of the MW antenna, on the other hand, may overheat and break. Due to the increased reflection from the VSWR load. Voltage Standing Wave Ratio (VSWR)

  1. The ceramic part will break down if the anode temperature exceeds its maximum rating. As a result, it’s critical to pay attention to how well the anode cools.

Magnetrons must be handled with care to prevent damage to the ceramic components.

It’s important to note that the thoriated-tungsten filament is typically in a coil shape, but this can vary. That’s why repeatedly heating it beyond its maximum rating can cause it to deform and become asymmetrical. 

More failures may occur if the operating temperature rises. An increase in filament current, an increase in power, and other mods are possible as a result.

  1. Burnout of electrodes is not an issue when the cooling system is sufficient to keep tube temperature below the maximum ratings.

Burnout of electrodes is not an issue when the cooling system is sufficient to keep tube temperature below the maximum rating. Temperature and flow switches in the cooling system’s protective circuit must always be checked to prevent tubes from being damaged due to system malfunctions.

 The filament and antenna of the magnetron must be properly cooled using the blower of the magnetron.

  1. Vacuum degraded by air leakage or discharge gas from the inner electrodes and the insulation materials is a common cause for poor emission or poor insulation at high voltage in tubes. 

Cracks in the ceramics, for example, can lead to a gradual glow or internal arcing if the seals fail. Keeping the magnetron cooled reduces the risk of magnetron failure due to reduced vacuum.

  1. Insufficient electron emission from the cathode will significantly decrease output power and modulation during operation. Improper cathode temperature, residual gas in the tube, and other factors contribute to poor emission.

The cathode is quickly contaminated by increased residual gas, which lowers emission quality. As a result of the increased evaporation caused by a hot cathode, a poor emission is also a result. 

When the cathode temperature is too low, insufficient electron emissions are produced, and the thoriated-tungsten filament is temporarily degraded.

The voltage of the filament or heater must be within the specified range. Because emission rejection is often caused by something other than what appears on the surface, exercising caution is especially important (e.g., poor contact, increased resistance of filament circuit). 

Excessive anode current results from supply voltage variations, exhibiting the same behavior as emission failure. Changing the supply voltage by more than a quarter of a percent should be avoided at all costs.

The drop in output power isn’t always a direct result of decreased emissions. Back bombardment causes secondary electrons to be expelled from the cathode. It can also be a cause contributing to the emission during operation.

  1. The decline in inefficiency is the primary cause of the drop in output power. Increased surface loss in the cavities is usually the result of deposits from the cathode or other components. 

The thoriated-tungsten filament’s asymmetrical shape and easy deformation could also disrupt the interaction space. As the temperature rises, so do the cathode’s evaporation, deformation, and asymmetries. This must be monitored and avoided at all costs.

  1. The MW electric field inside the tube can no longer maintain the oscillation in mode, which results in MODDING. This is frequently because of the unusual oscillation caused by the reflected waves from the load. 

Because the in-mode oscillation is interrupted when the cathode electron emission is inadequate, modeling results suggest that the microwave operator checks the circulator’s operation to avoid this.

 Regarding the load impedance, reflection, and load variation manufacturer’s advice should be sought.

  1. Generally, the tube can no longer control the electrons in the interaction space when a magnetron is operated with a larger reflection in the off-sink phase. 

Anode current is generated, but oscillation is not increased as a result. The term “runaway” is used to describe the phenomenon. Since a circulator and water load protect large magnetrons from reflected power, this is more of an issue for smaller magnetrons.

What Is The Life Expectancy Of A Microwave Magnetron?

According to industry standards, the typical life of a microwave magnetron tube is 2000 hours. When using a microwave oven, cooking and reheating food for 2,000 hours is feasible before the oven loses power.

Is It Worthwhile To Fix A Microwave Magnetron?

How new is your microwave, or is there only one fault with it? If the magnetron fails, you should consider replacing the entire thing.

 The heart of a microwave is the magnetron, and it is this heart that generates the microwaves. Replacing a magnetron will cost almost the same as purchasing a brand new microwave and in some cases, considerably more.


An odd buzzing noise can be a little frightening when microwaving your meal, but it’s a common problem many people experience.

When the microwave is turned on, radiation from the magnetron tube is emitted, which heats the food while producing no sound in most cases. An intermittent buzzing sound indicates it is wearing out or has already failed. 

Microwaves are particularly dangerous appliances because of the combination of high voltage and high current that they use to operate. It is recommended that you leave microwave repairs to skilled professionals, even if the job seems insignificant at the time.

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