These days, it’s hard to imagine a family without a microwave oven. But, like any technology, it sometimes fails. What to do if the microwave is buzzing and not heating? We will talk about this in detail in the article.
The most common reason is improper use. Before we eliminate them, let’s first get acquainted with the principle of operation of the microwave.
Microwave device
Its main blocks are:
- cooking chamber;
- door with seal;
- magnetron-generator;
- transformer-voltage converter;
- diode;
- capacitor;
- fan;
- backlight lamps;
- fan and pan motors;
- pallet;
- electronic control unit.
Food is heated in the oven by powerful electromagnetic radiation. The metal case and the metallized mesh on the door glass protect the environment and people from its impact.
As you can see, a microwave is a complex product created using high technology. Therefore, proper operation guarantees durable, high-quality operation of the device and your safety.
Terms of Use
To avoid possible troubles and breakdowns during the operation of the device, following simple recommendations will help:
- Do not use metal utensils when heating food (use only the one indicated in the instructions, and for liquids and raw eggs – closed containers).
- Load food into the chamber before turning on the oven.
- Always keep the inside of the chamber and tray clean. Perform preventive maintenance periodically.
- Change the parts of the unit in a timely manner if they have served their time.
- If power failures occur in the mains, use a stabilizer.
Fault definition
During operation, the microwave oven usually makes a little noise. Why she began to make strange sounds – a strong hum, buzz, creak, squeak or whistle, knock, you can answer by finding out the causes of the breakdown.
Let’s consider some of them:
- Over time, the turntable motor wears out. It either stops immediately or starts making unusual sounds.
- Noise when the platform rotates is sometimes made by the wheels of the stand. Especially if they skid on the contaminated surface of the chamber.
- The fan motor may also fail in the same way (in some models, the motor at the turntable and the hood is common).
- The air mixer in the stove ensures even distribution of heat. His motor is also subject to wear.
- The main part is the magnetron, generating microwave energy, which heats the products from the inside. In good condition, it works quietly. A defective one, as a rule, makes especially unpleasant noises.
Fact! This is the most important detail, which can only be changed by a professional master.
- The microwave oven stops heating when the high-voltage diode burns out. It is also better to entrust its replacement to a service center specialist.
- Significant noise can cause capacitor failure. If you yourself will make a replacement, be sure to discharge it before work.
- The reason for the lack of heating may be the fuse. This happens as a result of a short circuit on the magnetron, transformer or capacitor.
- The loud hum of the transformer is evidence of an overload in its winding due to a short circuit. This will be accompanied by the smell of smoke.
Practice shows that most of the breakdowns of equipment occur due to its improper operation.
With individual breakdowns, a person with special training is able to cope on his own. All you need is the necessary tools and devices, as well as the possibility of acquiring new parts. At the same time, consider the terms of the warranty for the device. If it has not ended, then by opening the seals of the microwave, you will not be able to contact the service center for repairs.
Repair Precautions
The internal structure of microwave ovens of all models and different manufacturers is almost the same.
To understand for a trained person is not difficult. However, it is worth remembering:
- Disconnect the microwave from the mains voltage before starting the test and discharge the capacitor.
- Do not turn on the device if the fan is not running.
- Do not start the magnetron with the door open and if the chamber is damaged.
- Since the radiation of the magnetron is very high, do not try to check its performance in the removed state.
- Install the parts of the equipment for replacement only with the same parameters as the burnt ones.
- After repairs, carefully remove unnecessary or replaced parts and debris inside the machine.
Remember that you can turn on the oven only with the chamber loaded. To test the functionality, place a glass dish with water there.
You will need:
- instructions with a diagram of the arrangement of blocks and components of the device;
- Phillips screwdriver
- passages;
- rubber gloves (you can use purchased at a pharmacy);
- multimeter.
Repair stages
After making sure that the microwave does not work, unscrew the bolts on the casing from the back wall. Carefully remove the case.
First make sure the fuse is good. This will show, after removing it, a thin wire inside. If it’s burned out, put in a new one.
Also check the condition of the electronics circuit guard. To do this, open the container and inspect the filament. Install new protection if necessary. In no case do not use “bugs”. Is it dangerous.
Now transfer the multimeter from standby to “ringing”. We bring one probe to a contact, for example, a diode, and touch the ground with the second. The “pierced” part will respond with a squeak. Correct will not show anything. Now we disconnect and replace the diode with a similar one in parameters and check again.
We do the same with the capacitor, not forgetting to discharge and check it.
The issue with the magnetron is more difficult. Its power is about 800 watts. It is he who generates the waves that give heat. Therefore, it is protected by a plate radiator and a thermal fuse. Determining its serviceability and the need for replacement is the business of a specialist from the workshop. You can only inspect the part for carbon deposits or obvious damage.
We hope our tips will help home crafters if their stove is buzzing, knocking, whistling or squeaking, or when the microwave does not work at all. Happy repair!