If the microwave does not work or does not work as expected, there are two ways to solve the problem. You can immediately seek professional help, or you can try to find the cause and eliminate it yourself. If you decide to go the second way, this article will help you.
Microwave operation. What you need to know for a long time
According to the statistics of service center masters, more than 90% of failures with microwave ovens occur due to improper operation. Let's repeat the most basic rules:
- Do not turn on an empty microwave oven.
- Do not cook whole eggs in the microwave.
- Cover the dishes. This will help keep the interior clean and prevent the screen from burning out. If the mica plate is burnt, it must be urgently replaced. Further operation can lead to more expensive breakdowns - to the burning of the magnetron.
- Use only specially designed cookware. It is strictly forbidden to load any metal objects. This also applies to metal rims on dishes and aluminum foil, and, it would seem, such trifles as staples on sausages, etc.
- Make it a rule to clean the inner walls of the chamber after each cooking. Use only detergents that are approved for use in the microwave.
Mica plate burnt out
The microwave does not heat food. What you need to check before the arrival of the master
The recommendations are as follows:
- Check the settings are correct. If you notice that the oven does not heat up, first make sure that you are using the correct mode. For example, you (or your household) could accidentally switch the mode to defrost. Naturally, in this case, the meat, fish (or other products) are slowly warmed up to room temperature.
- Check mains voltage. If it is low, the heating will be uneven. Network congestion is also possible. For this reason, you should not connect such a powerful device as a microwave oven with other powerful consumers. If the microwave does not even turn on, carefully inspect the cord and plug for damage. If the plug is melted, it must be replaced. Damaged wire can be wrapped with electrical tape. But this is a temporary measure until the arrival of the master, who will conduct a full replacement of the wire.
- The next reason is a broken door latch. Manufacturers have a safety feature: if the door is not closed, the device will not turn on. Try to press the door tighter. Trying to unlock the mechanism with a screwdriver is not a good idea - if you start the device in this condition, you risk burns and radiation.
The microwave will not work if the door is open.
Common reasons a microwave oven may not work
Microwave ovens from different manufacturers: Samsung, LG, Daewoo, etc. have their own characteristics. That is why the masters for a serious repair must seek a scheme for a specific model. But the principle of operation of this type of device is similar. Accordingly, the malfunctions are similar.
A microwave oven is a complex structure consisting of many electronic and electromechanical elements. Conventionally, the product design can be divided into several main blocks:
- Control block.Responsible for the selection of user modes, timer setting, is the center for processing and managing information received on the unit from various systems. This is where the control buttons, timer, etc. are located. Depending on what exactly failed, the equipment may not turn on at all or some modes will not be available.
- Microwave wave generating unit. Usually, when there are malfunctions in the generation units, you may encounter such problems: the furnace buzzes, sparks, or nothing happens at all.
- Plate rotation device. The most common failure in this unit is engine combustion. The light will burn in the chamber, the stove will turn on, and even warm. But the table will not move. Because of this, the products are heated unevenly.
- Microwave oven cooling system. Violation of the operation of these nodes can trigger the protection mechanism, which is why the device will not work.
The principle of operation of the microwave oven is as follows. After connecting the device, the mains current flows to the power transformer, which, in turn, significantly increases the voltage. After that, the magnetron comes into play. It generates radiation that is supplied to the chamber through a waveguide. Radiation affects the water molecules contained in the products. Molecules begin to move randomly, rub against each other, which causes friction and heat generation. This is how heating occurs.
The principle of operation of the microwave oven
Troubleshooting Procedure
Read the information on the display first. Modern models are equipped with a built-in self-diagnosis system. If a malfunction occurs, an error code is displayed on the display.
Important! Decoding of error codes is usually indicated by manufacturers in the instructions.
If you have an old model: a mechanical timer and a mode knob, you will have to conduct a complete diagnosis.
Problems with the control unit can be identified even at the stage of surface diagnostics. Usually the display does not work at all or its readings are erroneous. To protect the voltage-sensitive elements of the microcircuit, a fuse is integrated in the control unit.
Control board fuse
Check with a multimeter (in voltage measurement mode) whether power is supplied to the transformer input. If voltage is not supplied, the problem is with the computer. Electronics usually breaks down after power surges, so we recommend using a stabilizer.
The cause of many troubles is the failure of safety and control sensors. For example, a temperature switch or a steam sensor. Mechanical controls may oxidize or wipe contacts. To understand their characteristics and types, it is necessary to have a scheme for a specific model of a microwave oven.
Now proceed to check the mechanical timer. Set the multimeter to resistance measurement mode, set the timer and attach the probes to the output terminals - the device should show a different value from the original. The operation of the clock mechanism of the mechanical timer should be heard when the microwave is in the off state.
In this way, measure the contacts on all mechanical microwave control devices. Since the device consumes strong currents, relays are used to switch them. It must also be checked: measure the resistance of the coil, ring a couple of contacts.
If the above manipulations did not help to identify the problem, most likely the problem is in the blocks for generating microwave waves. It is the breakdowns in this node that are the answer to the question why there is no heating, and instead a roar is heard. It is important to distinguish malfunctions. The microwave will buzz when there is a malfunction with the magnetron, or when the magnetron burns out.
Important! Without proper knowledge, experience and skills, it is not recommended to climb into this node. The fact is that ultrahigh voltages (several thousand volts) are used here.Moreover, even when the equipment is turned off from the outlet, residual voltages remain on internal elements (for example, on a high-voltage capacitor).
The only thing you can try to do is replace the fuse. Remember that the new part must have identical characteristics.
Where is the fuse
To perform replacement manipulations, disconnect the device from the network, remove the top cover. Usually the fuse is mounted on two latches. Pulling the burned out element and replacing it with a new one is not difficult. When replacing a fuse, in order to avoid electric shock, do not touch other components, especially with bare hands.
