How to repair the microwave oven with your own hands: detailed troubleshooting and diagnosis

Microwave oven works on the principle of dispersion in the chamber of a small volume of microwave radiation, which causes oscillations of water molecules.

And following the law of energy conversion - a large amount of heat is released, which heats the food. That is, it is the liquid inside the food that is heated.

But if you do not use the microwave oven properly, sooner or later it malfunctions. The most common are sparks when you turn it on, as well as a decrease in the radiation power.

Is it possible to repair the microwave yourself at home? What you can do with your own hands, and when it is better to seek help from service centers

Repair the microwave with their own hands through the steps from A to Z in this article.

Good to know

The main element of the microwave oven is a magnetron, which is a transformer that converts current into high-frequency voltage. And it is this that is extremely dangerous for humans.

Accordingly, when disassembling the equipment or performing any work, you need to carefully observe safety precautions.

Basic requirements:

1. Be sure to de-energize the microwave before repairing it.
2. Always use earthing connections.
3. Do not disassemble the magnetron without proper experience and without using dielectric gloves.

There is a shield inside the body of the microwave that prevents microwave radiation from penetrating to the outside. And it is for this reason that the oven cannot be switched on when the door is open - this is a kind of a safety mechanism provided by the manufacturer himself.

But when you disassemble it, there is a possibility of closing the door lock mechanism. In any case do not turn on the open microwave oven!

Microwave oven construction

Conventionally, the microwave can be divided into the following key assemblies:

1. Case. Acts as a screen that prevents microwave radiation from penetrating outside the microwave oven.
2. Magnetron. Transformer that generates microwave radiation when voltage is applied.
3. Waveguide. A hollow, rectangular profile that directs a stream of microwave radiation directly into the chamber where the food is heated.
4. Condenser. Used in the power system of the magnetron. Capable of storing electricity. Therefore, even if the microwave is disconnected from electricity, it does not negate the possibility of getting an electric shock! It is strictly forbidden to disregard the safety rules.
5. Electric motor. It is responsible for turning the microwave plate during turning on to evenly heat the food.
6. Control box. Regulates the voltage supply, as well as allows you to set the microwave operation mode, duration, radiation power.
7. Control panel. A set of buttons or knobs, with which the user programs the microwave oven operation, indicates the desired heating mode.

These nodes belong to the most technically simple microwave ovens. But the functionality of each model is slightly different.

In modern microwave ovens, for example, manufacturers often add a heating element THEN to provide the possibility of cooking meat products, as well as a ventilation system, which distributes hot air inside the microwave oven.

The power button does not work

Possible causes of malfunction:

1. The microwave oven is not connected to the power supply. It is enough to check whether the power cable is connected to the socket and whether there is an electric current in it (you can use a multimeter by turning on the AC voltage measurement).
2. Failure of the control panel button. It must be replaced.
3. The door is not closed. Or the door locking mechanism is broken.

Control panel button failure

As a rule, the control panel is attached directly to the case with snaps, sometimes with 3 screws, and covered with a silicone thermal pad.

Quite often due to careless use of technology under it gets grease, dirt and moisture. That is enough to remove the panel and wipe the protruding contacts of the buttons with an alcohol wipe (using detergents is not recommended).

If you use a microwave that has no on button, that is, you just turn the knob and close the door, then most likely the knob itself is out of order. To replace it you will need to remove the control unit.

This is done as follows:

1. Remove the back protective cover of the microwave oven.
2. Unscrew the screws fixing the control unit.
3. Remove the protective cover from the front (if present).
4. Remove the plastic handles (in most cases, they are only held by latches).
5. Remove the control unit itself through the front.

After this you will be able to unscrew the fasteners of the handles and install new ones in their place.

The door is not closed or its locking mechanism is broken

The first thing to do is to check whether the door is closed tightly, whether its frame is free of any dirt, stains on the inside, clean it, if necessary.

You can use either alcohol or a special cleaner for microwave ovens.

If it is the lock that is the problem, you will need to remove the door. The lock itself is located near the control unit.

It is quite easy to remove the door, since most manufacturers mount them on external protruding hinges. That is, it is enough to unscrew only one screw (from above), and then - pull the door up.

But to remove and replace the lock you will have to disassemble the microwave and remove its front part.

To do this you must first remove the rear protective cover, unscrew the screws fixing the front panel and then unfasten it from the latches.

When the microwave oven is switched on, the circuit breaker of the electric panel is triggered

If when you turn on the microwave oven circuit breaker, that is, "knocks out" the electricity in the house, it indicates that there is a short circuit in the power circuit of the device. Most often - in the power cable or transformer.

The first thing to do is to visually inspect whether there are no traces of burns near the input wire, as well as on the plug itself (which is inserted into the socket).

If nothing of the kind is found, you will need to disassemble the microwave, remove the transformer and check it for a short circuit of the winding. Naturally, this should be done only with the proper experience and observing the rules of safety.

The transformer and magnetron are located in the back. That is, it is necessary to remove the protective cover, the holding plates (also fastened with screws), and then - in the mode of "testing" with a multimeter to check whether the transformer windings are short-circuited.

Sparks during operation of the microwave oven

If when you turn on the microwave inside the heating chamber sparks, and sometimes even electric arcs are visible, it could be caused by:

1. Grease or water getting on the walls.
2. Use of metal (incompatible) dishes.
3. Magnetron screen damage (mica).
4. Damage to enamel.

Any grease or water on the walls of the microwave.

The inner walls of the microwave are covered with a dielectric coating. Most often it is enamel or ceramic (the same enamel, but with the addition of ceramic chips), as well as acrylic (in "budget" microwave ovens).

And when fat gets on them, it can burn, thereby damaging the dielectric layer. That is, after that microwave radiation hits the metal part of the body, the microwave begins to spark and crackle.

Fixing the problem will require replacing the screen.

Metal utensils are used

For heating or cooking in microwaves you can only use dishes made of food plastic (on the packaging there is always a label indicating that it can be used for heating food in microwaves), as well as glass or ceramic.

Metal - can not, because it acts as a store of radiation, which causes sparks (current discharges).

Damage to the magnetron screen

In every microwave oven, the waveguide of the magnetron is necessarily covered with a mica screen. If grease gets on it, there is a chance of a burnout.

It is not difficult to check this, just inspect the plate (usually located on the inside right side). If it shows signs of burnout, it will need to be replaced.

Damaged enamel

If the microwave sparked, you should look carefully at the inside of the case. Even small scratches on the enamel will cause sparks as microwave radiation will hit the metal part of the screen. It will need to be replaced.

Decrease in microwave oven power

This occurs in two situations:

1. Breakdown of the waveguide.
2. Malfunctions in the magnetron power circuit or control unit.

Waveguide burnout

The waveguide directs the flow of microwave radiation to the food to be heated.

But it works properly only if there is no grease or other impurities on its walls.

Accordingly, if the microwave power decreased sharply, it is necessary to check its condition. If necessary - replace it (located directly near the magnetron, that is, you will need to remove the back wall).

Faults in the power supply circuit

In most cases this is due to the failure of the capacitor.

It needs to be replaced, because the current supplied to the transformer is undervoltage, so less microwave radiation is generated than necessary.

Timer does not work

The malfunction occurs in the following situations:

1. The digital control unit is defective. Relevant for microwave ovens, which have the setting mode with the buttons or the touch panel.
2. Timer and power selection knob is defective.

Control module defective

It will be necessary to diagnose it and replace it.

It is recommended to apply to the service center, since in most cases the breakdown is connected with the failure of the quartz element on the board. Repair in this case will cost inexpensive.

The timer handle is defective

You must remove the control box and replace the damaged knobs.

UHF Magnetron Repair

Failed magnetron, as a rule, is not repaired, but replaced with a new compatible one.

How to repair mechanical damage to the door

The door itself must be removed from its hinges. If the protective glass was broken - it can be replaced. Holds, as a rule, only on the latches (disassemble from the inside).

To replace the hinge (as a rule, it is only one, located at the top of the door) is enough to unscrew it (held on the 2 - 3 screws) and install new.

By the way, replacement doors for microwave ovens in most cases are sold already assembled with hinges.

How to replace the mica in the microwave yourself

It is recommended to replace the mica after about 3 years of regular microwave oven use or when it shows signs of burnout.

It is held in most cases with the help of 1 - 2 screws, as well as latches. That is, first you need to unscrew the plate, then - pick it up with some sharp plastic object.

The mica should not be thrown away, as it can be used to cut a new blank for installation in the microwave oven. Or you can buy a new one directly from the manufacturer.

To summarize, the general principle of microwave oven operation is quite simple. Most often it is the magnetron with transformer (replace), control unit (models that have mechanical control - more reliable), as well as the hinges of the door that fail.

And to significantly reduce the risk of any breakdowns with the microwave is recommended to clean it regularly. And use for this purpose special detergents for microwave ovens (they do not contain components that can harm enamel, acrylic or ceramic).

Bottom line, most microwave malfunctions can really be fixed yourself at home. Even if it is a serious breakdown, on the type of failure of the control unit.

To buy spare parts, even for older models of microwave ovens should not be a problem, with their supply manufacturers do not have any interruptions.

Useful video

On how to independently perform the repair of microwave, if it began to spark, in detail told in a video clip: