Chances are you probably put some dinner in the microwave to heat and focus on other things only to realize that the microwave switched itself off the moment you turned away, and the food is still cold.

You wondered what had happened, but since you were busy and tired, you brushed it off, thinking that you probably forgot to switch it on. You click that switch, and this time, keep an eye on it only for the microwave to go off right in front of you.

In this article, you will learn why the microwave keeps switching itself off and some of the things to check.

Let’s dive right in.

Check the Power Source

If the microwave switches itself off, the power source and connection are the first to start checking. Start by ensuring that the power socket has been switched on. Click it on and off twice to ensure that that is not the source of the problem. Next, check whether you plugged the power cable correctly into the power socket because a loose plug may switch the microwave on and off.

Next, proceed to check along the cord. Look for damaged, chewed, or exposed power cables connecting the microwave to the power socket. For safety reasons, remove the microwave from the power outlet when inspecting for exposed cables. Plug it back, and if you get a display, then you are good to go. If not, proceed to the next step.

You can fix the exposed cable by twirling insulated tape around the damaged area. Replace the entire cord with a new one if the damage was expensive and to avoid the risk of electrocution.

Check the Circuit Breaker

Repairing circuit breaker
Check the circuit breaker carefully for any switches that have been turned off

Sometimes the problem may not lie with the microwave alone but rather outside of the microwave. If you plugged in the microwave and it switched itself off again, you may probably have been tripped. Circuit breakers are safety measures installed in homes and apartments to guard against the effects of overflowing currents. In a power surge, the circuit breaker pops to protect the kitchen appliances using that power source.

Troubleshooting a popped circuit breaker is quite simple. Carefully go and open the door to the circuit breaker housing. Look at whether any of them has been switched off. If the answer is yes, look at the blueprint placed close to each circuit breaker. This blueprint should tell you whether the circuit breaker applies to the rest of the kitchen or to the microwave alone. You should have noticed that other kitchen appliances switch themselves off if the circuit breaker serves the whole kitchen.

A popped circuit breaker may indicate a larger underlying problem, and you need to call in your electrician. You need a multimeter when diagnosing possible issues on the exterior and interior because it helps keep track of continuity. Lastly, check the connection between the power cable and the back of the microwave, whether it is loose or broken. Once you fix the problem, put some water in a cup, put it in the microwave, close the door, switch it on and wait for some time. You have solved the problem when the microwave turns on and heats the water without going off again. If not, proceed to the next step.

Keypad Membrane

Circuit membrane
Check the conditions of the buttons and that they function and press normally

The microwave may have decided to press its buttons like rogue technology you see in those sci-fi movies. You should start by checking the conditions of the buttons, whether manual buttons are easy to press or are troublesome. It may be a problem of a button not coming out when you press it in, or some dirt and food particles have accumulated there over time if it is an old microwave.  If the standard buttons are functioning properly, then the problem is hiding in another place.

The more modern microwaves feature display buttons that are operated using heat sensors and may malfunction when the keypad gets old or if the microwave is wrongly placed. You may have placed your microwave above your stove or heat vent for easy reach. They are heating and cooking apparatus, after all.  However, the ambient heat rising from the stove while cooking may be messing around with the keypad, thus switching off the microwave mid-cooking.

If heat is the root cause of all the trouble, you need to consider the position of the microwave. This depends on two things : whether you recently bought the microwave or if it is an old one. IN some cases, the microwave may have been sitting on the stove forever without malfunctioning, which means that the heat resistance components originally placed in the keypad are old, worn out, and need urgent replacement. If you recently purchased a microwave, put it over the heat stove, and it starts misbehaving, consider returning it to the manufacturer in exchange for a more heat resistance version or a version that has special inbuilt sensors developed specifically for placement over heat sources.

 Before doing anything, you have to disassemble the entire touchpad to determine whether only the heat membrane is faulty or the whole touchpad. Some manufacturers require users to replace entire touchpads by giving little or no access to the membrane. Once you have judged what needs replacement, you can place your spare part order with the manufacturer or affiliated brands.

Control Board

Factory worker button
Replacing the control board yourself will save you money!

Did you know that the microwave has a brain, a thinking center referred to as the control board? The appliance relays and receives signals from power regulations and the commands you put through the touchpad from this center of thinking. As such, if the control board is not running properly, the appliance will display this problem through a myriad of symptoms, one of them being, you guessed right, the microwave switching itself off. When this issue happens, the control board is trying to relay information that all is not well and probably not enough voltage is present to supply the cooking component.

Start by unplugging the microwave from the power source for safety purposes when accessing the control board. Like the touchpad above, most microwaves dictate that you have to get a totally new control panel rather than replace the damaged part. If you access the control board only to find that you cannot open it or it’s sealed in a self-contained unit, then you will be forced to replace the entire control panel as opposed to the troublesome control board.

Accessing the control board will save you a couple of bucks since it means you can replace it yourself without calling a professional HVAC expert, which may even take time before you reach one. Any DIY fan can replace it with a bit of care by unplugging the cord from the old control board and plugging the wire harnesses into the new microwave while at the same time properly mounting and lining it up.

Overheating

Like all other ovens, the microwaves have pre-installed cooling systems, in this case, a cooling fan to keep the temperature of the magnetron under control. The cavity magnetron is the primary element of the microwave-take it out, and you literally have no microwave. A magnetron is an oscillator that emits electrons from the hot cathode whirling then past resonant cavities that form the anode at high speeds to generate the microwave energy.

Manufacturers design internal cooling fans to keep the temperature produced by the magnetron under control. If the cooling fan for any reason decides to rest and stop working, the thermostat may triple due to the magnetron overheating. As part of the safety mechanisms, the microwave will cause power interruptions and shut itself off until the magnetron cools down in between three to five minutes.

For this reason, experts advise that you fix the cooling system as soon as you can because the overheating will eventually blow down the magnetron, and as such, you’ll be left with no microwave. It is a rather intricate repair, and the best option is to get a certified technician to come and replace or fix the cooling fan.

However, if you aren’t successful enough in laying your hands on any virtual or physical issues, use a multimeter to troubleshoot for continuity issues with the doors. Check for signs of zero continuity or burning, and replace the door switch if you must. Lastly, hire a tech geek to get to the bottom of the problem because they come armed with tons of experience.

Check the Transformer

If all of the above are functioning perfectly, and the microwave is still switching itself off, the voltage transformer is probably malfunctioning. The transformer produces high voltage that charges the magnetron to emit radio waves that pass through the save guide, finally entering the food compartment to heat or cook your food. When the microwave keeps running for a short time, then stopping, the transformer may be short-circuiting. An awful smell will sometimes accompany the malfunctioning of a high voltage transformer.

If you have successfully reached the high voltage transformer, you should leave it and call a professional to handle the repair. The transformer usually retains a high amount of voltage even when switched off, and you don’t want to be messing with live current.

Malfunctioning Door Switches

If you didn’t know, closing the microwave door seals the door switches tightly so that the microwave can operate properly. A microwave running for a short time and then switching itself off might indicate that the door switches are loose or defective. The heat that the microwave produces to warm or cook your food may cause overheating of some components, one of them being the door switches which may also cause them to arch, thus preventing the microwave from running efficiently. Some ovens contain a gasket or seal around the door. Check whether the gasket or the seal is broken. You need to replace the seal or the entire door switches to solve this problem.

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Have a great day!

-Craig