DIY Rolsen microwave repair

In detail: do-it-yourself Rolsen microwave repair from a real master for the site my.housecope.com.

Many of us have forgotten about various stoves, hobs and completely trust the process of cooking microwave ovens. And this is not surprising at all: microwave ovens take up little space, have a rich set of different functions and significantly save time. Naturally, we are very upset when our microwave breaks down. The reasons for the breakdown and malfunction can be different. Consider what breaks down most often in a microwave oven. Often, if a microwave oven breaks down, it is necessary to contact a specialized master. After all, this is not the simplest device, so the repair is rather complicated. But in fact, the design of a microwave oven is elementary and includes only a few basic elements. If you first familiarize yourself with frequent breakdowns, then repairing the microwave on your own will not be difficult.

Although the design of a microwave oven contains a lot of elements, most of them do not play a special functional role. To repair this device, you only need to know the basic elements of the circuit that ensure its operation. Among them:

Magnetron.
Transformer.
High voltage fuse.
Rectifier diode.
Capacitor.
Control block.

Arrangement of elements in the microwave

It is easy to distinguish them, because outwardly the design is not very complex. The magnetron is always installed in the middle, directed towards the food warming unit. The transformer is located under it, representing a massive box with a protruding coil. The capacitor, diode and fuse are located to the right of it, and the control unit is often located near the input panel.

Video (click to play).

When the device is turned on, a voltage of 220 V is supplied to the transformer. Passing through the primary and secondary windings, a current of 2 kV is already flowing out of the element. Further, the negative half-wave goes to the diode, and the positive one charges the capacitor, which again leads to a twofold increase in voltage. After that, the generation of microwaves by means of a magnetron begins. The power of the magnetron is regulated by the control unit.

Therefore, in the event of a breakdown, it is worth paying attention to these elements. They carry the greatest load, so they are often the problem.

When disassembling the microwave, be sure to disconnect it from the mains.

Search for breakage in a microwave oven is based on "symptoms". This allows you to gradually eliminate possible causes and find the real one. So, if the oven does not turn on at all, then it is worth checking the following points:

The integrity of the power cord.
Door position and closing system.
Mains fuse and thermal relay status.

In the first case, the situation is elementary - there is no power supply due to damage to the power cord. A similar situation occurs when the outlet is damaged or overloaded. In this case, it is enough to replace this element, everything is in order with the microwave itself.

Next, it is worth checking the operation and position of the door. The fact is that the operation of a microwave oven when the door is open is dangerous for others. Therefore, the design provides for the possibility of operation only when it is completely closed. If a latch, a locking system or a checking element is broken on the door, the protection system will not allow the device to start.

The last points also concern the protective systems of the oven. The fuse prevents damage to the device due to power surges, and the thermal relay provides a complete shutdown of the system when the door is open. Both can fail, it is quite easy to replace them.

It is also worth checking the voltage in the network and the number of devices connected to the outlet. The microwave oven is very demanding on power supply, therefore its slight deviations can interfere with the operation of the appliance.

Procedure if there is no heating

Fuse faults

Most models suffer from common problems and have similar, typical faults. For example, if the microwave works, but does not heat, then this indicates a malfunction of the capacitor, diode or magnetron. To repair a microwave oven yourself, you will need a simple set of tools: pliers, wire cutters, a screwdriver, an adjustable wrench and a five-spanner wrench, as well as a soldering iron with the necessary equipment.

When repairing a microwave microwave yourself, you should remember about safety measures. The two most important hazards in microwave oven repairs are high voltage in oven components and microwave radiation. Do not turn it on if the door is defectively locked or the mesh on the viewing window is damaged. Do not make independent holes in the case and introduce any conductive objects into the units and elements of the furnace. Never touch internal parts and assemblies while the microwave is in operation. Be sure to use a tester or other electrical meter to measure AC and DC current.

If the above reasons are not confirmed, then you need to disassemble the device for troubleshooting. Before that, be sure to turn off the oven from the network and wait a couple of minutes.

Fuse

What should you look for when searching for breakdowns? There are several basic elements that often fail:

Circuit breakers.
Capacitor.
Diode.
Transformer.
Magnetron.

Photo of a microwave condenser

These elements are directly involved in the operation of the device and were mentioned earlier. First you need to check the health of the fuses. Their breakage can be seen immediately, because during combustion, the conductor inside is destroyed. If this did not happen, then it is worth looking further.

For further verification, you need to take a multimeter, because outwardly it is extremely difficult to find a breakdown on the remaining parts. To check the capacitor, you need to switch the device to ohmmeter mode, and then connect it to the part. If there is no resistance, then the part must be replaced.

High voltage diode

It is impossible to check the high-voltage diode with a tester. It is recommended to replace it in case of breakage of other parts, because often the blow falls on it. It can be checked in a slightly different way - by connecting it to the network on the way to the light bulb. If the light is weak or blinking, then the part is working properly. If it burns brightly or does not turn on at all, then the diode must be replaced.

Next, the transformer is checked.

Photo of a microwave transformer

It is important to observe safety precautions, because

Photo of microwave magnetron

this element is able to hold a charge for a long time. It will take several minutes to discharge a serviceable transformer, and if the discharge resistor breaks down, it will take much longer. It is worth discharging it on the case or not touching it at all if there is no experience with such a technique.

Next, the transformer windings are checked. It is necessary to remove the terminals and check the terminals of the device one by one with an ohmmeter. First, the primary winding is checked, for which the rate varies from 2 to 4.5 ohms. For the secondary winding, the limits are 140 and 350 ohms. It is also worth checking the filament winding by connecting the terminals leading to the magnetron to the multimeter. The norm here varies from 3.5 to 8 ohms.

All previous tests have failed, then the problem may lie in the magnetron.

To test the magnetron, just connect the tester to its power terminals. The tester switches to ohmmeter mode.If the resistance is 2-3 ohms, then this means a breakdown of the device. The situation is the same if the tester reads infinity. In both cases, the device must be replaced.

These items are the most common culprits in microwave oven breakdowns. However, the failure of the device is often associated with other malfunctions, such as problems with the electronic control unit, timer and other electronic parts. Here, simple checks with a multimeter will not help; the help of a qualified technician is needed. Although it is much easier to simply replace a part if you are sure that it is broken.

There are frequent cases of breakage associated with the destruction of the cap on the magnetron. The thin aluminum body simply cannot withstand stress and is destroyed by microwave waves. This problem often occurs in older devices that are more than a few years old. The obvious symptoms in this case are noise and sparks during the operation of the device.

To check, it is enough to remove the transformer, because the cap is located towards the food chamber. If the cap is destroyed, then there are 2 options:

Cap replacement.
Flip the cap.

The first option is a priority, it is enough to order a replacement or return the magnetron for repair. The second option is considered a temporary alternative that allows you to extend the life of the device indefinitely. It is enough just to rotate the cap 180 degrees around the axis, because the load falls on only one half.

Repairing a microwave oven is a feasible task for a novice electrician. If the problem lies in the breakdown of one of the constituent elements of the furnace, then the simplest and correct solution is to replace it. The bottom line is that most of the parts of this device cannot be repaired, but only completely replaced with a new one. This especially applies to fuses, diodes and capacitors - the main reasons for the failure of the device.

Parts replacement is carried out in several steps:

The microwave is disconnected from the network.
The transformer is discharged (5 minutes).
The terminals are disconnected from the defective part, it is removed.
A workable part is connected to the same place.

There are two important factors to consider when replacing a part. The first is schema compliance. It is important to remember that each part has its own characteristics, selected for the performance of the entire electrical circuit. If, after replacement, this nuance is not taken into account, then this leads to new breakdowns. This is especially true for the transformer and capacitor.

The second important factor is the connection of the part. It is necessary to connect the replacement correctly, keeping the previous arrangement of the terminals. Reconnecting the device in reverse order can damage it, as well as several other parts in the system.

This will restore your microwave in most cases. If the breakdown is related to the electronic part of the device, then you should contact the professionals. This will ensure quality repairs and prolong the operation of the device for a long time.

The most common malfunction is the failure of the waveguide cover in the microwave oven chamber. This is caused by splashes from cooking. This starts sparking between the magnetron antenna and the protective cover. Untimely removal of burnt products leads to local burnout of the lid and to complete destruction.

Local burnout of the lid mica plate can be removed with alcohol or solvent 646. It is enough to gently wipe the burnout area.

Burning out mica

If the mica plate of the lid is clearly in poor condition, is greasy or begins to paint, then it should be replaced. Removing the diffuser plate is a snap. This can be done using an ordinary sharpened knife. Usually, the mica plate is attached with a self-tapping screw or rivets. Carefully place the old plate on the new template and cut out a new one.The best way to do this is with a knife - you can break the mica with scissors. We make holes in the new plate with a sharp screwdriver and process the edges of the fields of the plate with sandpaper. We install the new plate in place of the old one.

The question often arises, how to replace mica for microwave ovens? For these purposes, any dielectric with a similar dielectric constant is suitable. For example, PTFE or Teflon.

Common breakdowns in a microwave oven are also malfunctions associated with other elements of the oven. For example, such as the keyboard of the oven control unit, the microwave oven electronic control unit and the dissector. Less often, the high-voltage capacitor and transformer, the microwave waveguide plug and the rotating pan fail. The power supply and magnetron of the microwave oven are subject to wear and tear.

Knowing how to troubleshoot microwave ovens can save you significant repair costs. However, if you do not know how to repair the microwave yourself, then it is best to contact a specialist. Specialized service centers will help you to repair a microwave microwave oven. In addition, watch the video on microwave repair, perhaps there is exactly that breakdown that will help you fix your beloved household assistant.

Repairing a microwave oven requires special professional knowledge and skills. But with a little knowledge of the basics of electrical and radio engineering, knowing how to use an electrical installation tool, and you can try to cope with this problem, even if you are a builder, musician or doctor. To make repairs with your own hands, just remember what you were taught at school in labor lessons. In this case, it is necessary to observe the rules of electrical safety: do not make short circuits by connecting the wires, and do not stick your fingers into the outlet. If you are not sure of yourself, then it is better to contact the service center to specialists.

Before we understand the reasons for the breakdown, let's first understand the design of the microwave oven. It is very simple and consists of 4 basic elements:

Magnetron;
Waveguide;
Transformer winding;
Food warming chamber.

It is this set of elements that is the engine of the microwave. And if it is malfunctioning, you should look for the cause in them.

After connecting the microwave to the network, a voltage of 220V is supplied to the first winding of the transformer. The voltage is automatically transferred to the secondary winding. The chamber heating system starts up. Due to the fact that these two windings are isolated from each other, the safe operation of the microwave oven is ensured.
The microwave oven allows food to be heated at high speeds by using twice the voltage. In this circuit, the main role is played by a capacitor, to which a diode is connected in parallel. The duration and magnitude of the temperature regime helps to control the temperature sensor and a regular timer.
For safe use, a power protection relay is built into the oven, the function of which is to stop the microwave oven when there are high voltage drops in the mains or when the door is open. If this whole description seems complicated to you, then do not worry: now we will figure it out.

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Most often, external signs of a microwave oven failure are the appearance of sparks, puffs of smoke, stopping the rotation of the plate, and the absence of heating food placed in the oven. Or the microwave just won't turn on. In this case, plugging it into the network is dangerous!
There are three main reasons for the failure of an electrical appliance:

Blown fuses;
Defective magnetron;
Burnout of the mica plate.

With this type of breakdown, you can repair the oven if you follow the instructions strictly. First, consider the functional diagram of the microwave oven.

We take a functional diagram becauseit is easier to understand the principle of operation of the microwave oven, it is universal, regardless of the brand of the oven, it is simpler in comparison with the schematic diagram of the microwave.

And the location of the microwave elements can be seen from this figure:

If the backlight works in the oven, the plate rotates, but the microwave does not heat the food, then, most likely, the cause of the malfunction is a malfunction of the magnetron. In the above diagram, the magnetron is designated "magnetron".
A magnetron is a device that generates microwave radiation. That is why, in the event of a failure of this part, the stove does not heat up.

The magnetron is housed in a small rectangular metal case. First, you need to clean it, and then make a visual inspection. Next, inspect the magnetron unit itself. Namely, the integrity of the wires connecting the terminals and the case. Often the reason for the inoperability of the magnetron is the failure of the bushing capacitor. See below a video on how to repair a microwave oven magnetron with your own hands:

A sure sign of a broken mica plate is sparks that appear when it is turned on. The reason is improper operation of the oven, that is, heating food with an open lid. With this option, drops of food are sprayed onto the plate. As a result, it gets wet and burns out. Image - DIY Rolsen microwave repair

The mica plate is inexpensive and can be purchased at specialized electric stores. If you find a mica plate of other sizes, then you can make a plate of the desired size with your own hands from it.

If you cannot find a replacement for this part, you can reuse the burned-out plate. To do this, it is necessary to remove the plate and carefully clean it from dirt. Then turn it over with the damaged side inward and carefully put it in place. This repair option, of course, can hardly be called ideal, but it will do quite well until the moment when you find a replacement for the damaged part. How to replace the mica plate, watch the video:

Do not rush to throw away the burned-out magnetron, it may need to be repaired.

If the upper cap is burnt out or partially destroyed, the microwave cannot be generated in a controlled stable mode, which leads to an emergency situation and triggers the protection. Installing a new element (cap) is a standard procedure. If, after carrying out this operation, the broken magnetron still does not work, it means that it is completely out of order or does not generate sufficient emission.

You can completely tidy up the microwave radiation unit as follows:

Purchase a new magnetron from the corresponding microwave model. There are different delivery formats. In one configuration, only the magnetron is purchased, and in the other, a waveguide is attached to it.
Install a magnetron of suitable parameters. Pay attention to clear geometries and power. For example, Redmond uses various standardized series of radiators, so replacing the main, so to speak, heating element is not difficult.

The work of the emitter is based on electron emission... This is tube technology. Therefore, the magnetron is constantly depleted, the emission rate decreases, the heating rate of food decreases. You can manually extend the life of the main element of the furnace by adding windings to the winding of the power transformer, which will lead to an increase in the voltage on the emitter. This should be done carefully. The maximum voltage for which magnetrons are calculated is 6.3 volts, the minimum is 3.15 V.

For Sharp and Redmond microwave ovens, exceed this limit with caution, winding half a turn of the winding. Other brands may allow an increase in magnetron voltage up to 7 Volts... Using this method, you can not only repair the microwave, returning it to its previous performance, but also extend the service life of the radiation system up to 3 years.

One of the most common problems is damage or burnout of the mica platecovering the waveguide window. Such a malfunction can manifest itself in different ways, ranging from arcing in the chamber or the electronics unit, to the failure of the microwave to work in a given mode due to the activation of the automatic protection. It is very easy to fix the plate. It is enough to remove the damaged part and contact service centers or specialized stores.There you will be cut out a piece of a suitable size from a large sheet of the appropriate thickness, you just need to install it in its original place.

Other problems and methods of neutralizing them look like this:Poor button or control panel performance can be remedied in two ways. If the furnace is equipped with contact mechanical switches, they must be cleaned, check the connection contacts. If we are talking about a film control panel, it is possible that the tracks have oxidized and deteriorated over time. Repair of the film control panel of a microwave oven is carried out in the same way as repairing a computer keyboard. There are various conductive, silver-containing varnishes, pencils for troubleshooting. In the simplest case, if the tracks are very weakly damaged, you can use a simple graphite pencil (for more details, see the article on what to do if the buttons on the microwave do not work).Before disassembling the microwave oven and checking the condition of its internal components, make sure that there is power. The procedure is standard. The plug is inspected, the fuse is checked, you need to make sure that there are no kinks, scuffs, or visible fractures of the core on the power cable. Separately, the places where the wire exit from the plug and its entrance into the case are examined.Only after the presence of power, the integrity of the cable and the microwave fuse have been checked, can you proceed to further inspection and repair. It is worth remembering: accuracy, attentiveness and adherence to the rule "from simple to complex" will certainly lead to a good result of diagnostics and repair.

To repair a microwave oven, you need to have a general idea of how it works. Microwave oven repair begins with removing the top cover. Before that, you should take care of completely disconnecting the device from the power supply, only then proceed with the elimination of breakdowns with your own hands.

When these steps are successfully completed, a transformer with two fuses will open for access: one is located directly on the part itself, it is fusible, the second is located nearby on the very body of the microwave oven, made of ceramics. Also next to the transformer is a doubler block consisting of a thick capacitor and a diode. The whole set of these elements is the power supply circuit of the microwave oven magnetron.

Carefully! Do not touch the condenser immediately after removing the top cover. This element is capable of holding voltage for a long time, which can easily lead to an electric shock. When repairing a microwave oven with your own hands, this factor should be taken into account.

The peculiarity of microwave ovens is that all parts are connected in series. First, you should pay attention to the above magnetron and its power supply circuit. After removing the protective housing, a transformer with a large capacitor located next to it becomes accessible. There will also be a ceramic, low-melting fuse, a diode. The magnetron operates according to this high voltage circuit. Under no circumstances should you get into it with your hands, tools. After a complete de-energization, the capacitor will lose its residual voltage, the likelihood of an electric shock will decrease.

The primary winding of the micro-transformer takes over 220V. As a rule, its location is at the bottom. You can recognize it by the coils of copper wire, which will be bare in appearance. However, it is not. It is covered with a transparent insulating film. The location of this coil is under the secondary winding.
The microwave oven has two secondary windings. On one of them, several turns of a simple wire are usually not neatly wound. This heats up the cathode. Here the AC voltage is only 6.2V so that the electrons can be lifted from the surface.But where there is good insulation, there is a high voltage winding. About two kV directed towards the exit.
A capacitor shunted by a diode is located at the output of the circuit. The action of the negative half-wave falls on the cathode, the action of the positive half-wave charges the capacitance. Further, the electrode is subjected to double voltage, which is removed from the capacitor and the micro-transformer. As a result, approximately 3.5-4 kV is created. This power is enough to start the generation process.

You should be extremely careful, the output winding is always parallel to the magnetron, which has two output options. But the grounding of the anode is done in a separate way.

Thus, this is what happens:

the heating coil has 6.3V;
at the cathode stays up to 4.2 kV, grounded by the anode.

All microwave ovens have an electrical connection for the cathode, the heating coil. Each microwave oven is equipped with a timer that controls the magnetron power. The use of a start relay is used in order to avoid the occurrence of a spark. Next, you should pay attention to the front panel.

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The most likely breakages occur in the area of the mica plate. Energy is supplied from the magnetron to the waveguide along the rod. The latter is highly sensitive to the presence of various food debris. All these contaminants begin to ignite, emit sparks, thereby disrupting the stable operation of microwave ovens. To avoid unforeseen situations, the developers decided to close the waveguide with a mica plate. It has soft, flexible properties, relatively affordable pricing. It will not be difficult to fix such a breakdown with your own hands. You can buy material of any size, cut the corresponding segment. The peculiarity of the mica plate is that it transmits a frequency level of 2.45 GHz without obstacles. It is at this frequency that the microwave oven operates.

Also, mica plates do not get wet. This is a very important factor if liquid is heated inside microwave ovens. After all, water very quickly absorbs the radiating frequency of 2.45 GHz, there is a danger of serious damage. If the water reaches the waveguide, a big accident is created, which will not be easy to repair with your own hands. The high-voltage fuse will blow instantly. If things get worse, the magnetron itself burns out, other electronics that power the microwave oven.

What factors influence the destruction of the mica plate? Most reheated food contains a lot of fats, oils, and other such ingredients. They differ in that instead of the usual boil, they shoot out greasy drops. Once such a drop hits the mica plate, a small wire bridge is created. An electric arc is formed: from the waveguide to the mica plate, then from it to the body of the microwave oven. As soon as pops and sparks, uncharacteristic for the operation of stoves, appear, this is a sure sign that the stove will soon need to be repaired.

Anyone who has tried to fix the microwave with their own hands wondered about the high-voltage fuse. The mechanism of microwave ovens of this kind triggers at least two fuses:

If you look at the electronic board of the microwave, this part appears as a small white or transparent cylinder. Its task is to protect integrated, wall-mounted microwave oven components. This small cylinder is also part of the power supply circuit. Its burnout occurs in the event of a capacitor breakdown, a resistor short circuit.
The circuit that forms the power supply of the magnetron includes a diode, a transformer, and a capacitor. Through them, about two or three kilovolts approaches the cathode. These details are not difficult to find. It is difficult to confuse the appearance of the capacitor with anything else. This is a huge detail in the form of a jar weighing up to one hundred grams.One diode leg is attached to it, the other is fixed to the body. Nearby is also a small barrel, often ceramic, painted in brown. It is this barrel that contains a high-voltage fuse inside it. Its task is to prevent overheating of the magnetron. When a mica plate breaks through or a metal spoon is placed in the microwave oven, the high-voltage fuse immediately burns out.

It is best not to try to assemble the high voltage fuse with your own hands or remove it from the electronic board. This practice is extremely dangerous for people. The microwave oven may stop working and there is a high risk of fire and electric shock.Before you start talking about repairing a fan that cools a magnetron, grills or an illuminating lamp in a microwave oven chamber, you should also pay attention to the protective relay. Their task is to turn off all operating systems at the moment when the chamber door is in the open position. Two relays usually break the power supply circuit. And one relay will be controlled by the functionality of the second. The work is carried out as follows:

If the oven door is open, the relay trigger is released.

In this operation, the power supply circuit has two breaks.

The second relay closes the ground on the phase.

When the first relay is energized, nothing bad will happen as the power supply circuit is in the open position.

When the first relay sticks, the fuse is blown out. This is due to the fact that the ground was short-circuited by a phase.

The fuse is not meant to be on top of the magnetron or inside the case, but on the board. To fix a microwave oven with your own hands, you should check the operation of the protective relay. Without this functionality, access to the power supply to the magnetron is practically impossible. The task of the power fuse is to take into account the movement of current in the magnetron. In the event of a dangerous situation, the protective element burns out, the generator breakdown is excluded. A similar situation occurs when the microwave oven is idle or there is some kind of metal thing in its chamber.

Of course, any hostess and owner will be offended if the microwave oven suddenly stops turning on or malfunctions. The first thing you want to do is take your favorite device and go to the nearest workshop or service center. If the microwave is under warranty, this is exactly what you should do, and if not, then you will have to pay for the repair.

But as practice shows, most faults have very simple reasons and a person who knows how to use the tool and has it can make simple repairs on his own. But for this you need to know the principles of microwave operation. Let's see why this useful device may not work?

The main malfunctions of a microwave oven are the result of improper use or neglect of the appliance. Factory defects most often appear during the warranty period and therefore are eliminated by service centers free of charge.

Never and under no circumstances should you run the microwave oven magnetron with the door open, if the chamber or waveguide is damaged.
You should never, under any circumstances, even try to connect a magnetron removed from its original place. It is life threatening!
It is forbidden to start the microwave oven with the fan off. This could damage the magnetron.
It is possible to make any manipulations with the parts of the furnace only after disconnecting from the network and forcibly discharging the high-voltage capacitor.
All elements must be replaced only with similar ones.
After completing all the work, you need to remove all, even the smallest, objects from the waveguide.
Do not start the microwave oven without load. A non-metallic container with water must be placed in the chamber.

When disassembling the microwave, it is best to take pictures of each step, so that later you can easily restore the original position and attachment of all parts. Digital cameras and mobile phones will be of help here.

Let's consider how to find out the possible causes of such a breakdown. In this case, first of all, you need to check the supply voltage to the power filter card. To do this, after removing the casing, the high-voltage capacitor is discharged (a mandatory operation after each network connection) and the power cord is ringed with a multimeter. All three wires from the socket to the terminals should ring out. The grounding terminal on the socket must ring out to the microwave oven body. You can read about how to troubleshoot a capacitor here.

If the wire is intact, then you can check the integrity of the mains fuse, which is most often located on the power filter board and, if necessary, replace it with the same rating. But it should be borne in mind that the fuse does not just burn out, there is some reason that led to an overload.

In any case, you need to carry out a visual inspection of the insides of the microwave. To do this, you need to arm yourself with a flashlight and a magnifying glass and carefully consider all the elements.

When the microwave turns on and works, but for some reason does not heat up, this may indicate malfunctions in the high-voltage circuit or the magnetron itself. But before checking these components, you should carefully examine the camera. It should not contain any dirt, worn out enamel, burnt holes. On the left side of the camera there is a rectangular window made of a special radio-transparent dielectric. This plate must be removed and examined carefully.

First, you need to clean it from contamination with alcohol, and then make sure that there are no through-burn holes or darkening from the effects of electrical discharges. If there is, then, firstly, this part must be replaced, and, secondly, this eloquently suggests that the microwave oven could be started without loading, or metal objects were placed in the chamber, or timely cleaning was not performed.

In the high-voltage circuit of the magnetron, there are such important elements as a transformer, a high-voltage capacitor and a diode, as well as safety diode, which burns out during abnormal conditions. It is very easy to find it near the transformer, where it is placed in a special container. His appearance will immediately show his condition. When replacing, it is necessary to purchase a safety diode only with equal ratings.

High voltage transformer ringing should be done only with the load disconnected and the primary winding. It is very simple to disconnect it - you need to remove the terminals with pliers. The resistance of the primary winding should be about 1.5 Ohm, the secondary high-voltage 110-120 Ohm, and the secondary heating winding less than 0.1 Ohm. If any of the windings does not ring, then such a transformer must be replaced.

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Magnetron has a connector that connects it to the transformer. Having disconnected the terminal, it is necessary to ring the resistance between the terminals and the case, and if they ring out, then this indicates a breakdown of the through-line capacitors in the filter. The filter can be changed as an assembly, or the capacitor of the required rating can be changed separately.

Having removed the magnetron from its original place, you can assess the condition of the antenna cap, and if it is burnt out, it must be unambiguously replaced. Only you need to change it to exactly the same size - this is very important! At the same time, you can assess the state of the magnetron insulator. A broken antenna or his case unambiguously suggest the replacement of the magnetron.This can be economically disadvantageous if the microwave has a long lifespan.

If, after all the measures taken, the microwave oven still does not start, then you can proceed to the diagnostics of the locking system. First, the tightness of the microwave oven door and the reliability of the locking are checked. This is done with a sheet of writing paper. When closed, the paper should be pressed along the entire perimeter of the door so that it cannot be pulled out or with great difficulty.

The adjustment is made in two places: from the hinge side and from the lock. It is necessary to achieve a complete and tight fit, otherwise the microwave radiation will penetrate beyond the microwave. Then the microswitches are monitored in the open and closed states - they are called by the tester. If at least one is faulty, everything changes anyway, since they have approximately equal wear.

If all attempts to start the microwave oven in the power supply circuit and the high-voltage part have not been successful, then you can proceed to checking the control unit. The control board is removed and its visual inspection is performed with a magnifying glass.

Most boards have their own fuse that may have blown. The condition of the tracks, the presence of burning and swollen capacitors, broken diodes and zener diodes - all this indicates problems. The power transformer can only be called by removing it from the board.

Given the variety of models and circuits of microwave ovens, further recommendations for repairing the control unit will be meaningless. Each case is unique and if the owner does not know what to do next, then it is better to entrust everything to specialists and, at the same time, think hard about the fact that it should have been done better from the very beginning.

A microwave oven is a complex and high-tech device that requires careful handling and unconditional fulfillment of all recommendations given by the manufacturer.
Self-repair is possible only when the owner of the microwave has knowledge in electrical engineering and electronics.
During repairs, safety rules should be observed when working with increased voltage and microwave radiation.
Replacing a magnetron in a microwave oven that has served for more than 5 years is economically unprofitable.

See how easy and cheap it is to repair this device without service if the breakdown is minor.

Video (click to play).