Why does the fuse burn out in the microwave oven?

HomeBlogWhy does the fuse burn out in the microwave oven?
24MayNCR 3 1

Microwave oven greatly simplifies our life. The device not only allows you to quickly heat cooked food but also to cook a variety of dishes. It can also have additional functions, for example, a grill, which allows you to use it as a full-fledged oven. However, like other appliances, the microwave can fail. One of the most common malfunctions is a blown fuse. There can be several reasons why a microwave fuse blows, but it is usually caused by a power outage.


Microwave fuse function


The microwave oven is a technically complex device. It allows you to quickly heat food in a short time. It uses quite a lot of electrical power. To ensure safety and protect the device from power surges, a special fuse is used. If it fails, the microwave is completely inoperable. To repair it is enough to replace the faulty part with a new one.


Diagnosis of the microwave oven always begins with the fuse, since most often its blowing leads to a malfunction. This part is an important element of the electrical circuit, designed primarily to protect other components. Fuse elements are divided into several types. Special fusible variants are installed in microwave ovens.


The main functional element of the fuse is a filament of special metal enclosed in a cylindrical glass case. There are contact points on the ends of the casing to include the part in the circuit.


If an excessively high voltage is applied to the circuit, the metal filament melts and the power supply is cut off. This protects other parts from failure due to power surges.


When the voltage is normal, current flows through the metal filament to the other components. All oven components are connected in series. The fuse is usually one of the first elements in the circuit.


If the voltage rises too much, only the fuse breaks. The other components are momentarily disconnected from the power supply due to filament burnout. Consequently, the burning of the fuse can not be considered a breakdown, but rather a tripping of the protection system. To restore the microwave oven’s performance, it is sufficient to simply replace the burnt part. But, sometimes other parts located in the network in front of it can also burn out. In this case, it will also be necessary to replace all the failed elements.


Causes of a blown microwave fuse


In most cases, the fuse element blows for one of the following reasons:


– A power surge. This is especially true in areas where there are frequent power outages. If a higher voltage than the maximum allowable voltage is applied to the unit, the fuse will blow momentarily, resulting in the complete disconnection of the unit from the power supply;


– The switches installed for closing the door are defective. They seal the heating chamber to prevent microwaves from escaping into the environment. These waves are dangerous for humans and animals. When the microwave is turned off, these switches are actuated, allowing the door to open. Microwave ovens most often have 3 of these switches. They work due to special springs. In case of wear of the latter, the opening function is triggered with a delay, which can also burn out the fuse.


Rarely, the breakdown is due to a short circuit of the power transformer. It is the transformer that generates the microwaves. If the transformer is shorted, the fuse also blows instantly to ensure safety. Failure of the transformer is very rare and is usually caused by the gradual wear and tear of the part.


Blown fuse replacement


There may be several fuses in the design of the microwave oven, which depends on the model. Most often, manufacturers install 3 fuse elements. Identifying a blown fuse is very easy due to the transparent housing. Inside it will be visible darkening and contact disruption.


You can disassemble the microwave oven only after disconnecting it from the power grid. Next, you need to remove the back cover. The necessary elements are at least in the following nodes:


– control board;

– power supply unit;

– between the capacitor (made in the form of a barrel) and the transformer (has a winding of thin copper wire).


Some models may have more fuses. They are identified by their characteristic appearance.


Only a fuse with similar characteristics can be installed in place of a defective one. A similar part with a lower rating may blow even when the main’s current is normal. A part with a higher rating, on the contrary, may not work during a critical voltage surge.


After installing the new part, you must reassemble the case to check the operation of the unit. It is forbidden to turn on the microwave oven in disassembled condition, it entails health risks.


Blowing a new fuse immediately after replacement may be due to the following reasons:


– Unstable mains voltage. In case of constant failures it will be advisable to install a voltage regulator;


– Failure of another part. In most cases, a high-voltage diode, transformer, or magnetron becomes unusable.


In the second case, do not try to repair the machine yourself if you do not have the appropriate skills and knowledge. You should contact a professional technician to repair such breakdowns.


Want the best microwave repair in San Diego County? Give us a call! We are a leading service provider due to the excellent quality of work performed by our technicians. We use only quality parts recommended by the manufacturer of the microwave. Forget about any discomfort with our friendly and professional team. With us, you get the highest quality service and the friendliest approach. Our highly qualified staff will do everything to make you forget about any problems with your microwave. They are our problems now.


Contact us


(442) 291-2244


[email protected]

Our specialist will perform the necessary repairs right in your home. We are pleased to offer a 90-day labor warranty to all customers after we repair an appliance.

Subscribe to our news, you will receive personalized discounts

Our specialist will perform the necessary repairs right in your home. We are pleased to offer a 90-day labor warranty to all customers after we repair an appliance.

Subscribe to our news, you will receive personalized discounts
©2024 Oceanside Appliance Service Center. All Rights Reserved.
Scroll to top