DIY microwave repair: detailed instructions and video

Microwave - an excellent assistant in the kitchen. She cooks, fries, defrosts and warms up food. It becomes sad if she suddenly stops working. How to be Carry to the workshop? They will definitely ask for a lot of money. Microwave repair often costs just below the cost of a new device. What to do? Try a microwave repair yourself.


  1. Microwave device
  2. Principle of operation
  3. Popular causes of breakdowns
  4. Replace Items

Microwave device

Repair at home stove begins with the analysis of the device. So what is included in this rectangular device?

  • chamber with a plate for products;
  • door (the element has a seal);
  • power cord;
  • magnetron (generates energy);
  • high voltage fuse;
  • a device that converts energy (transformer);
  • rectifier (high voltage diode);
  • capacitor;
  • fan.
What a microwave consists of

Secondary Elements:

  • grill lamps;
  • fan motor;
  • backlight lamps;
  • engine pallet.

These elements have a serial connection. Opening the lid of the device, the main element, the magnetron, will be visible to the eye. It is powered by the following circuit with high voltage: transformer, fuse, huge capacitor, diode.

Principle of operation

  1. The primary winding of the transformer (coiled copper wire) is located below. It has a voltage of 220 V.
  2. Further in the circuit are two secondary windings. One of them (cathode heating) is a coiled copper wire near the primary one. It has 6.3 V. This AC voltage stimulates the electrons to act off the surface. The other winding is located a little higher. Here 2 kV. The voltage goes to the output.
  3. The output of the circuit blocks the capacitor shunted by the diode. This analogy of the arrangement of the elements gives the following action: the negative half-wave goes directly to the cathode element, and the other, positive, charges the capacitance. Gradually, a voltage of 4 kV is obtained, and the generation process begins.
  4. The cathode receives voltage from the secondary heating winding of 6.3 V. The magnetron anode is attached to the ground. The spiral, which performs the function of heating, is electrically connected to the cathode. The power of the magnetron element is controlled by the timer of the device.
  5. The programmer controls the operation of the device. It has a gear that controls the time. The longer the magnetron device element operates, the more power is given to the dish. And vice versa, if the magnetron does not work much, then it produces the same amount of power.
  6. When the door is opened, the operation of the device stops. The protective relay is responsible for this process.
  7. A high-voltage fuse protects against idling and tin objects. In case of an accident, it burns out.
  8. The above secondary mechanisms are connected in series. This fact makes it easy to repair microwaves with your own hands. Since, if at least one element does not work, then the whole device does not perform its functions. An exception is the starting relay and magnetron.

Popular causes of breakdowns

The device cannot turn on

Why did it happen? Because such an element as a fuse has broken.

How to repair a microwave? Replace with a new fuse. After the indicated action, check the safety diode of the transformer and the transformer for serviceability.

How to find a fuse in the device? This is a glass can with thin wiring and a small spring inside. In working condition, the spring is stretched. Plastic sleeve protects the fuse.


How to check the performance? Disconnect the fuse from the circuit and check with the car battery and the bulb for the size of the bulbs. The lamp is on - the element is working, off - not working.

The clock on the display works, but the device does not heat up

Why? The point is the breakdown of the small door switch.

How to solve? Replacing a broken item with a new one or (if possible) repair.

The device turns on periodically

How to accurately recognize the problem? The device will turn on first, and when a few minutes pass, it will turn off. The process is repeated in a circle.

The point is a cooling fan that has stopped working. It may break the on relay or the ventilation holes may be closed.

Solution: replace the item with a new one.

Sparks are visible from the camera and smells of burning

The reason lies in the contamination of the mica pad. Dirt caused the element to burn out.

In this case, you will have to repair the device by replacing the burned element.

Microwave does not heat food

The device cannot heat food due to low mains voltage or loss of magnetron emission.

Repairing a breakdown will require special equipment (such as a voltage stabilizer). Question: Is it worth repairing a broken microwave yourself? Everyone should answer it independently. With a positive decision, it will be necessary to increase the number of turns or completely replace the magnetron.

The microwave display does not work

In the event of a breakdown, the display does not fully reflect the values, with spots. Most likely, the processor that needs to be replaced is damaged. In favor of the processor is the fact that the device does not turn on.

Another option: a breakdown of the screen itself.

Control panel does not work

The touch panel displays the operating time of the device. If it does not work, then the paths that conduct current are damaged.

Touch panel repair is reduced to the complete replacement of broken elements or to the laying of wires.

The pan does not spin smoothly

If the plate inside the microwave does not rotate smoothly, jerkily, then the grooves on the rollers are dirty. Another reason: the engine broke down.

Output: clean the grooves of the rollers from contamination or replace them with a new engine. Also read the article, what to do if the dish in the microwave does not spin.

What the engine looks like, its components, how to disassemble and repair it you will see in this video:

The light inside is on, the plate is spinning, but the food is not heating

Reasons: a large voltage drop, changes in the power circuit, breakdown of the magnetron.

How to solve? It is necessary to ring the transformer circuit and eliminate the detected problems. The second solution: replace the generator.

Control panel buttons do not work

In this case, do-it-yourself microwave repair comes down to carefully checking the circuit with a tester, replacing broken buttons and soldering the contacts.

Extraneous hum at work

The reasons for the breakdown of the following elements: fan, transformer, diode.

How to solve? Replace items.

The microwave does not turn off

Diagnostics: the device is constantly working and cannot turn off.

What is broken? The cause is a malfunction of the feed relay.

How to fix it? Replace the relay. Before that, check the breakage with an ohmmeter. There may also be a reason in the processor itself or the control circuit.

Replace Items

Are broken items easy to replace with new ones? Where to get these items? In any specialized store. If you find it difficult to name the item, disassemble the device, take the broken part to the store, show the seller. He will help you in the right choice.

For do-it-yourself repairs, the most expensive will be the purchase of a capacitor (about 600 rubles), and the cheapest - a fuse.

Interesting to know: what is convection in the microwave.

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