Microwaves can have a lot of different issues and which combination of issues happens at the same time will help determine exactly what the root cause is. There could be times when the issues are two separate cases so you may need multiple components fixed.
There is one main reason for an LG microwave not heating and making a clicking noise. The magnetron has likely gone bad. This is the one component where its failure would cause the microwave to both not heat and make a clicking noise.
Read further to understand what you should look at and when you should call a repair technician.
What Is the Magnetron?
All microwaves have a component called a magnetron. This part uses extremely high voltage with a lot of DC. Power is used to produce the microwave frequency to cook food. A burned-out magnetron means the oven won’t heat.
You can’t repair a magnetron. This part must be replaced if it’s burned out. Also, an average person can’t replace the magnetron because of the amount of voltage the appliance carries even after it’s unplugged.
The capacitor holds more than 4,000 volts and it must be discharged before any internal work can be done. That is a dangerous task that only a professional should perform.
Other Possible Issues
The diode takes the power from the A/c power outlet from the transformer to D/C power. It also doubles the voltage in the process, creating 5,000 volts that go to the magnetron.
A faulty diode means the magnetron isn’t getting enough power to heat your food properly. A diode will look like it’s burned out if it’s bad. You can visually check it but it’s best to get a professional to test it and other components of your microwave.
Another component to blame for no heat would be the capacitor. However, that won’t produce a clicking sound. A burned-out capacitor will cause the entire circuit to quit working.
The capacitor is a high-voltage part that partners with the diode to turn the voltage from the transformer into DC voltage and then double it.
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Main Control Board
One possibility that is always involved in every microwave malfunction is that the main control board has failed. This is a problem often misdiagnosed. It is an unusual problem for the control board to go bad. It is typically one of the other problems and most home experts advise that you seek to replace them before replacing the control board.
Are There Any Other Issues It Could Be?
Any number of part issues can cause your microwave to fail to heat but none of these would cause the clicking sound. Some other part issues could be door switches, high-voltage transformer, thermal fuse, and thermoprotector.
The reason why these parts could cause your microwave to not heat is that they are all involved in producing and transferring heat.
Door switches relay signals that cooking may begin because the door is shut. The transformer produces the energy. The thermal fuse and the thermoprotector both cut power if the oven overheats.
It could be that any of these parts have given out and that causes a chain reaction within the microwave to cause the magnetron to also burn out. However, none of these parts on their own will cause the symptoms described.
None of those failures will produce a clicking sound. Only a faulty magnetron will do that.
What Should I Do?
There are some initial things you can do to try to fix this yourself and to make sure the oven will need repair by a professional. Here are a few things.
Testing the Oven
Test the oven with a cup of tap water for 60 seconds to see if it heats at all. If it is warm but not hot, it could be your power settings that are the problem. It wouldn’t be the magnetron or the diode. If the water remains unheated, then you are looking at a repair.
Try Resetting It
You should always try to reset your microwave before calling the support center or service tech. That will be the first thing they will ask you about so you might as well do it before you call.
Unplug the microwave from the wall and wait three minutes. Plug it back in. Reset the clock. Then, test it again. Listen to see if there is a clicking sound and check the water for heat. If one or both symptoms remain, call the support center.
Calling the Support Center
Most people dread calling any type of support center. It can be an easier phone call if you have some things in front of you. You will need to model and serial number. It is also best if you have the owner’s manual nearby because they may refer to it.
Those with warranties should have that information too because the magnetron is one of the more expensive repairs. After talking with the service center about the problem and trying all their solutions, ask for a service center near you that is licensed and qualified to do the repair.
How much would this type of repair cost?
Most experts put the price of replacing a microwave magnetron between $100 and $200. The part is one of the more expensive ones costing between $50 to $100. Labor will cost around $100.
Part of the expense is because it takes someone trained to replace the magnetron. this is the primary microwave component and there is stored voltage involved.
What will a service technician do?
The first thing a service technician will do is test the microwave. He or she may also go through the reset process. However, then the service technician will dismantle the microwave to get to the magnetron. The tech will test the magnetron and other major components with a multimeter to see if all have continuity.
This is to see if any other parts need replacing along with the magnetron. It isn’t uncommon for several parts to start going bad at once.
Is the magnetron worth replacing?
You have two options. You can replace the magnetron or buy a new microwave. A microwave oven will not work without one.
The choice of replacing or rebuying is one you will have to weigh based on the cost of the repair versus the cost of a new microwave. It is worth the cost of replacing a magnetron in some cases with a newer, expensive microwave,
Are LG microwaves cheaper to repair than other brands?
The LG brand microwave is, on average, cheaper to repair than other major brands. The cost of repairing an LG microwave oven is between $100 and $400. Other brands, like Panasonic, KitchenAid, and Viking, can cost upwards of $450 to $500 to repair.
How long does a magnetron last in a microwave?
A magnetron typically has a life of around 2.000 hours. Considering most frozen meals can be cooked in under six minutes, that would be roughly 20,000 meals.
Why is my microwave making a buzzing noise?
The buzzing noise is a sign the magnetron is about to fail. You will hear a loud buzzing as this component goes out. However, your oven will still heat. Once it fails, your microwave won’t heat and you will hear only a clicking sound.
The Variety of Sounds from a Microwave
A failing magnetron can produce a variety of sounds. Typically, the sound it produces is a low hum when working properly. However, if the magnetron is about to burn out or is damaged, it can produce a buzzing sound or high-pitched squealing noises. It can even emit a growling sound.
Prepare to repair or replace it when your microwave starts making a lot of noise.