The Elenberg microwave oven does not heat. The microwave does not heat, but it works

Why doesn't the microwave heat up, but the plate rotates and the light is on? The fan is humming and the food is cold. What to do and where to go? When the equipment, which now costs a lot of money and is very necessary in the kitchen, can not be thrown out, but simply repaired, all the knowledge on repairing electrical appliances is used. For achievement positive result only basic knowledge of the device itself and microwave electronics is required, well extreme case basic skills of searching data on the Internet.

There are a number of reasons why the microwave stopped heating and it’s not a matter of broken parts, for example:

1. The network voltage has decreased. The operation of the microwave oven, as well as its heating, can be affected by slight decreases of 20V. As a result, the plate will be heated, but there will be no food in the middle of the vessel. The issue of power outages can be resolved in one day: you just need to go to the store and buy a power supply.
2. The network is overloaded. If two powerful appliances are running from the same outlet at the same time, an overload occurs. This issue can be resolved by installing another outlet.
3. The door is out of order. As a result of a broken latch, the door does not close tightly and the microwave does not heat food or heats it poorly. Here you can try to repair or completely replace the latches.
4. Incorrect mode selection. Very often, after defrosting mode, they forget to switch back to microwaves. Defrosting does not heat the food to the required temperature, and you are already about to disassemble the appliance.

Complex microwave malfunctions: looking for the true cause

Often the microwave works, but does not heat food because the magnetron has failed. Next on the list will be a capacitor, a fuse, and a transformer also often breaks. The reason for poorly reheated food may be the following:

• the timer or the control unit itself is broken;
• due to breakdown of the transformer and other parts;
• The inverter may be faulty (this only applies to inverter microwaves).

The microwave oven does not heat and makes a loud noise

If you find that the microwave oven turns on but does not heat and makes an unusual sound (for example, buzzing), there are 3 explanations for this:

• The diode has become unusable. This part does not allow current to pass in the opposite direction; the current moves only in one direction. If this part fails, the appliance begins to buzz and does not heat the food;
• it's time to change the capacitor. A capacitor failure leads to the generation of waves and the device hums;
• magnetron failure. A defect in this part may also cause a buzzing or humming noise.

If you decide to find the reason and repair the microwave yourself, then keep in mind that this is a dangerous device. Even if the microwave is unplugged from the network, there is a high probability of electric shock of high voltage, up to 5,000 V. If you have doubts and are not confident in your own knowledge, then it is better to show the device to a specialist, even for diagnostics alone. There is no need to risk your life, because the device is not worth it.

If you nevertheless decide to produce, then before watching anything, turn off the device from the network. Be sure to find the instructions, which contain the names of all the parts that are there.

The microwave does not heat: check the fuse

First of all, after removing the cover, you need to make sure that all fuses are working properly. If you see that they have turned black or the thread has burned out, then you just need to replace them. Often there are two fuse parts inside.

When buying a new part, be sure to take the old (burnt out) one. To temporarily solve the situation, it is not recommended to make bugs out of wire. There is a great danger of fire, and the price of a good fuse is no more than 50 rubles.

If the device hums when turned on, there is a possibility that the capacitor has broken. It’s easy to check its serviceability: you need to take an ohmmeter and connect it to the part. If everything is in order, then the ohmmeter needle moves. And if it stops, then the capacitor has failed, and because of this the stove is noisy.

Before replacing or checking the capacitor, it must be completely discharged!

If you notice a burning smell or something crackling inside while the microwave is operating, after watching this video you will understand what’s wrong. It shows how you can repair a microwave oven if it sparks.

High voltage diode

Often this device is not checked due to the complexity of this procedure. Easiest to buy new part, but before that, make sure it is broken. You can check using a capacitor, which should not heat up. Also, a sign of a diode malfunction may be a hum when turned on and a blown fuse.

Magnetron

If, when checking the device, you did not find any breakdowns, then it is likely that the problem is in the magnetron. The sign by which magnetron failure is determined is strong noise (hum) during operation of the device. If the microwave is humming and not heating, then you need to look at the magnetron to see if there are cracks or carbon deposits there. If the breakdown is not visible visually, then check with an ohmmeter. If the magnetron burns out, then you need to buy the same one. It should have the same parameters and size.

Preventing damage

We have shared with you information on what to do if the microwave works but does not heat food. It is very important to determine the reason and problem why the microwave stopped heating food. Most often, you don’t have to look for an answer for long: most likely, you used the device incorrectly.
In order for your equipment to serve for a long time, you should not do the following:

• heat food in a metal container (a spoon also applies here);
• turn on an empty device (without food);
• warm eggs;
• place containers with lids.

Over time, any equipment can fail due to wear and tear of spare parts. Equipment made in China can quickly break down due to shoddy assembly; they are used to making quality work only for themselves. If the price of equipment is quite ridiculous, then remember the expression that the miser pays twice. In conclusion of the article, we would like to give you advice: if your microwave oven is under warranty, then under no circumstances open it and do not start looking for a breakdown yourself. Trust qualified employees who will perform diagnostics and carry out work at the expense of the company.

Even if you feel that you can repair the device yourself, know that there is a great danger in any incorrect action. The device has the ability to accumulate electricity and can shock with high voltage. Trust professionals who can determine the problem even just by looking at the device. Your life is much more valuable! Think twice before opening the lid.

If after turning on the light is on, the plate is spinning, the fan starts humming, and the microwave does not heat, this does not mean that it should be thrown away. Most likely the reason lies in violation of operating rules. Any housewife can cope with such a malfunction. But even if any part fails, you can find out what the reason is and restore functionality yourself.

If the microwave works, but the food does not heat up, it will be useful for you to know that often the source of trouble is not only violations of the rules, but also external factors:

1. Insufficient supply voltage. Deviation from the 220 V standard may be caused by an overload of the supply line if several electrical appliances are connected to it at the same time. When the voltage drops by 5 - 10 V or more, the microwave operates, but does not heat. The problem can be solved by laying a separate power line, but with constant changes in voltage in the power supply network, it is better to purchase a special power supply of appropriate power.
2. Door malfunction. Over time, it stops closing tightly, so food cannot heat up to desired temperature. In this case, you need to monitor the tightness of the closure. If the oven stops heating even with the door tightly closed, it means that the latches that turn on the magnetron have broken off and need to be replaced.
3. Setting the wrong mode. If you do not switch the mode after defrosting food, you will not be able to get hot food, since it is not intended for heating.
4. A metal object hit the camera. It could be a spoon or fork forgotten in food. Therefore, the microwave sparks and stops heating.
5. Switching on with an empty chamber. In this case, sparks fly more abundantly than in the previous one and heating problems begin.
6. Using cookware that is not intended for heating. Such dishes, especially closed ones, may explode due to overheating, scattering the contents throughout the chamber. As a result, parts fail and the operation of the microwave is disrupted.

To make repairs yourself when the breakdown is caused by the failure of any part, you need to know how the microwave works. The high-frequency radiation that heats the food is created by a magnetron connected to the chamber by a rectangular waveguide. Depending on the model, it is closed on the camera side with a piece of mica or a plastic cover.

The high-voltage power supply is provided by a transformer using a multiplier consisting of a capacitor and a diode. Protection against overloads and short circuits is provided by a fuse installed in the high voltage circuit.

The magnetron is cooled by a fan. Heated air enters the chamber through the air duct, which accelerates heating. To remove excess air and steam, holes are made in the chamber that are impenetrable to high-frequency vibrations.

To eliminate the possibility of turning on the oven with the door open, a lock is installed on the microswitches. They supply power when they are turned on by pressing the latches installed on the door when it is closed. When opened, the power turns off instantly.

Depending on the manufacturer, the number of switches ranges from 2 to 5. They are used in the furnace switching and power control circuits. Common cause The reason why the microwave does not heat is a damaged microswitch in the magnetron control circuit. To illuminate the chamber, a lamp installed in the air duct opening is turned on.

Work commands are selected on the control panel. The choice is made by mechanical switches or by a microprocessor. Digital control can be done using buttons or using a touch-sensitive selection option. If the panel breaks down, it will not be possible to repair it without skills in working with electronics. But everyone can check whether any wire has come loose.

Troubleshooting

If the microwave breaks down and does not work as it should, you should not immediately take it apart. First, you should look for a solution in the user manual. It contains a list of tips on why the oven may fail. If there is no hint, you need to start by checking the voltage in the socket, since, as already mentioned, the operating mode of the magnetron depends on its value.

If the voltage is normal, you need to disconnect the microwave from the power supply and use an ohmmeter to check the micro switches that are activated by the door position.

When doing your own repairs, you should take into account that a voltage of up to 5000 V may remain on the capacitors of the microwave, even if it is not turned on. Therefore, immediately after removing the cover, they must be discharged by shorting the terminals with a piece of insulated wire.

Checking fuses

To get to them, you need to remove the back cover by unscrewing the mounting bolts. First, check the mains fuse. If it burns out, the light in the camera will not light. If it is not smoked and upon visual inspection the wire inside is intact, it would not hurt to check with an ohmmeter to be completely sure.

It would also be a good idea to check the integrity of the power cord and plug. Then the high-voltage fuse located under the casing is checked, again with an ohmmeter. The presence of a small resistance indicates that it is intact. Faulty fuses are replaced with new ones, but not with “bugs” that can cause a fire.

Multiplier check

The multiplier consists of a diode and a capacitor. The condition of the capacitor is checked with an ohmmeter, although it is intended for use in alternating voltage circuits. If the instrument needle first deviates a little and then shows infinity, everything is fine. The presence of slight resistance indicates a breakdown. If there is an internal break, the needle remains at zero. A malfunction of this capacitor often causes the microwave to hum but not heat. Since it is difficult to check the diode at home, it is better to immediately replace it with a known good one.

They are placed on a high-frequency lamp. First, they are discharged by closing the output of each container to the housing with a screwdriver with a plastic handle. Then, using an ohmmeter, one probe of which touches the housing and the other the capacitor terminal, the serviceability of the elements is checked. If the reading is 0.1 ohm, the part is working. When zero it will have to be replaced. By connecting the microwave to the network and placing a glass of water in the chamber, at the same time they check the primary winding of the transformer. The voltage at its terminals in heating mode should be 220 V.

Checking thermostats.

Checking the magnetron

If the microwave hums but does not heat, one of the reasons may be a malfunction of the magnetron. This lamp generates high-frequency radiation with a frequency of 0.5 - 10 GHz, which heats the contents of the chamber. A malfunction of the magnetron is often the reason why the microwave does not heat, but works, what to do.

You should not immediately blame the magnetron, since even with famous manufacturers (LG, Samsung, Panasonic), when the lamp is running, the soldering points of the filter coils and feed-through containers may be damaged, or the power supply contacts may oxidize. Malfunctions of this kind are easy to fix yourself.

If the contacts are not oxidized and everything is in order with soldering, you need to check the filament with an ohmmeter. Its resistance should be within 2 - 3 Ohms. If there is a break, the device will show infinity.

It should be taken into account that the housing and radiator of the magnetron heat up to 150°C during operation. Therefore, if the oven was turned on, for example, a transformer was checked, you need to wait until the lamp cools completely.
If after checking the oven does not heat food, you need to replace the magnetron. To do this you need to write it down specifications, which are placed on the back cover of the microwave or on the lamp, and contact the workshop. If you have the necessary skills, you can make the replacement yourself, but it is safer to invite a specialist.

On video: magnetron repair.

Mica plate inspection

If, after a complete check and replacement of faulty parts, the oven turns on, the light starts to burn, the disk with the dishes rotates, and the microwave does not heat the food, you need to check the mica plate. It covers the exit of the waveguide into the chamber, through which radiation from the magnetron travels. If there is carbon deposits on the plate, it interferes with the passage of electromagnetic waves, and in case of serious damage, sparks and even the formation of small lightning may occur.

Using such an oven may cause a fire.. First of all, it must be removed by unscrewing from 2 to 8 screws. If a visual inspection does not reveal holes, cracks or other damage, you need to clean the darkened areas with fine sandpaper. Then the plate must be cleaned of dust and put in place. To be sure, you can rotate it 180°.

If there are one or more holes.

This part can be purchased inexpensively in the store. Perhaps in a new plate, if it is, for example, from Samsung, but you need it for Sharp, you will have to drill holes for screws. When working, remember that mica is fragile and can break if handled carelessly.

In the video: The microwave oven works, but does not heat, a detailed analysis of the reasons.

Let's imagine a situation: when getting ready for work in the morning, you are left without a hot sandwich: the microwave does not heat the food. Outwardly, everything is in order - the stove lights up, turns, but does not heat up. Let's figure out what the problem is and what to do in this case.

How does a microwave oven work?

First, let's explain the principle of its operation. The basis of the machine is a magnetron, which creates an electric field. It acts on the liquid molecules in the product. They start to move. When they rub against each other, heat is generated. Due to this, as well as the use of additional devices, the equipment performs many functions - heating, defrosting, grilling and others.

Rules for caring for a microwave oven

1. Do not use metal containers or metal-coated utensils for cooking. The oven, acting on them, heats the dishes themselves, and not the food.
2. Do not place eggs, vegetables, fruits or other foods that contain a lot of water in open containers. Heating from the inside, they will burst and splash the camera.

1. To avoid fire, do not turn on the appliance without loading food.

Causes of malfunctions

Even products from such well-known companies as , cannot last forever. Practice shows that the equipment of these manufacturers, like Sharp, Scarlet, Panasonic, Supra, Bosch, works perfectly for 5–7 years. Then problems may arise.

For example, outwardly everything seems to be working, but the food is poorly heated or not heated at all. In this case, the unit makes noise or squeaks, but at the same time the stand rotates. It takes a long time to heat food. Such signs do not always indicate that the microwave is broken and needs to be taken in for repairs. We need to find out why it doesn't work. Let's go from simple to complex.

• It happens that the user, in a hurry or because of forgetfulness, did not switch the mode on the display from defrosting to cooking. As a result, the oven heats poorly.
• For normal operation, a mains voltage of 220 Volts is required. A drop of even 10–20 Volts will result in the stove not heating well. Use a block uninterruptible power supply or .
• Sometimes owners simultaneously connect several electrical appliances to the network using tees and extension cords. Then the socket cannot withstand the load, the equipment does not warm up well or turns off. Use a separate power source for each device.
• If the microwave heats up less well or only heats up every once in a while, the reason may be a loose fit of the chamber door. The latch needs to be adjusted.

If all this does not help, let's look deeper into the problem and try to find the cause of the breakdown. The microwave oven hums, buzzes, stops heating, but still works if the following are out of order:

1. Door switch.

1. One of the fuses.

1. Diode or capacitor.

1. Magnetron.

The problem may also be in the inverter, if you have the appropriate type of microwave.

Some problems you can fix yourself, while others are better handled by a specialist. Statistics say that in four out of five cases, after self-repair, you still have to contact a workshop.

DIY repair

When starting work, make sure that the warranty period for your equipment has expired, otherwise you will lose the opportunity for free service at the service center.

You will need:

• Screwdriver Set;
• pliers;
• soldering iron;
• ampere-voltmeter;
• rubber gloves (thin household gloves are fine).

First, re-read the instructions. For example, the passport of a Samsung microwave oven discusses the causes of common malfunctions and explains how to eliminate them.

Attention! A microwave oven uses high voltage current. Even when disconnected from the network, it remains on the capacitors for some time. Therefore, after de-energizing the device, wait 10 minutes or discharge the parts.

After removing the screws on the back wall, carefully remove the housing cover. Inspect the device carefully, using a flashlight if necessary. An unpleasant smell of burning insulation, obvious deformation of parts, cracks or leaks will immediately indicate the location of the breakdown.

If the listed signs are absent, start searching.

First of all, measure with a voltmeter mains voltage and ring the heater wire.

Use a tester to check that the operating voltage is at primary winding of the transformer also 220 Volt.

Visually inspect the fusible mains fuse. The absence of thin wiring inside indicates that it has burned out. You can check its resistance with a device.

Now let's move on to testing multiplier consisting of a diode and a capacitor. The ampere-voltmeter needle, which has deviated to the maximum, indicates a working capacitor. If it breaks down, the part must be replaced along with the diode.

Before checking pass capacitors Use an electrically insulated screwdriver to connect their terminals to the housing. We touch the contact of the part with one probe of the measuring device, and the metal with the second. The sensor should show no resistance. This means the capacitor is working. After that, we check it for breakdown. There should be a resistance of 0.1 Ohm between the contacts of the capacitor.

After turning on a glass of water for five minutes in the microwave chamber, measure the voltage in the primary winding with an ampere-voltmeter transformer. It should be 220 V.

Having purchased parts that match the parameters in a specialized store or radio market, replace the faulty ones using a soldering iron.

And finally, test magnetron. When examined, its breakdown is indicated by carbon deposits. If this is not the case, look at the soldering points of the coil contacts and connections to the capacitors. Strip or solder them. The resistance of the assembly filament during testing should be 2–3 ohms.

Do it yourself essential element The microwave oven should not be changed so as not to permanently damage the equipment!

Determining the reason why your device stopped heating and repairing it, if you have experience and the necessary tools, you can do it yourself.

If it stops heating, do not rush to blame the manufacturer for low-quality internal parts - very often the cause of the malfunction is more than trivial:

• Voltage level drop in the network. Even a minimal decrease in voltage, by 15-20 V, can negatively affect the performance of the microwave - due to lack of energy, it simply will not heat up fully. If voltage drops in the house are regular, it is advisable to use an uninterruptible power supply.
• Network overload. If two or three powerful appliances are connected to one outlet, there may be a network overload, due to which the oven will also not receive additional power. The solution to the problem is to connect each device to a separate outlet.

• Door damage. Very often, the reason for the loss of functionality of the microwave is a malfunction of the door, or more precisely, its latch. It’s all simple: the door does not close tightly, so the oven chamber loses its seal and the heating of the food is significantly weakened. Replacing the latch will help fix the problem.

In all three cases, the reason for the poor functioning of the microwave lies not in the deformation of its internal devices, but in external problems - all of them can be solved without any repair work.

But if none of the proposed options suits you and after a thorough check the device still refuses to heat, then you are dealing with a breakdown of internal elements: fuses, capacitor, diode or magnetron - we’ll figure out how to solve the problem if each one fails from these devices.

Malfunctions of internal elements

Before you begin troubleshooting, be sure to disconnect the microwave from the power supply and prepare the device’s instructions - you will need it to figure out where certain parts of the oven are located. Then you can proceed to maintenance:

• Circuit breakers. Remove the back panel and visually assess the condition of the two high-voltage fuses: if the glass casings are blackened or the internal filaments are burned out, the elements are no longer usable and need to be replaced. You can buy them at any hardware or construction store.

Important! So-called “bugs” cannot be used instead of deformed fuses - they increase the risk of fire hazards.

• Diode. To check the performance of the diode, you need to evaluate the condition of the high-voltage capacitor - if it is very hot, then the diode needs to be replaced. A more complex way to check is to measure the resistance using a multimeter, but this is a rather troublesome undertaking for household maintenance.
• Capacitor. If the microwave starts buzzing loudly after turning on, but does not heat up, then the problem is in the capacitor. To check it, you will need an ohmmeter: connect the probe of the device to the capacitor - if there is resistance, the ohmmeter needle will begin to deviate, and if the needle does not move, then the element has failed.

Advice. Before starting to test the capacitor, completely discharge it: short-circuit all the terminals in turn with an indicator screwdriver.

Magnetron failure

If, after checking all the above-mentioned elements, no problems are found, there remains another option - the magnetron. This is the key device of the microwave oven, so it is fair to consider it separately.

In good condition, the magnetron emits electromagnetic waves, under the influence of which the contents of the oven chamber are heated: the waves activate the hydrogen atoms contained in the food, and they begin to move, contributing to an increase in temperature. If the magnetron is damaged, the microwave either stops heating altogether or produces a very low temperature.

There are several reasons for magnetron malfunction. The first is filament deformation. To check it, measure the resistance of the thread with an ohmmeter: the device shows 2-3 Ohms - the threads are fine, the device shows infinity - the threads are broken. The second is the wiring of the induction coil contacts. Such a malfunction is easy to detect even visually, and it can be corrected by re-soldering.

The third reason for the malfunction is the most serious - magnetron burnout. If there are cracks or even a layer of carbon on the device, then there is no point in repairing it - you need to replace the device. Before you go shopping, write down the technical specifications of your furnace and the magnetron itself - this information can be found on the back panel. In particular, the following data will be required: filament voltage, power, anode current, filament current, cathode voltage - if the new magnetron does not meet these characteristics, it will not only not be able to function normally, but will also most likely provoke deformation of others furnace parts.

As you can see, if your microwave works but does not heat, there may be several reasons - in one case it will take you a couple of minutes to fix the problem, and in another you will have to look for new parts and undertake repairs. The main thing is to correctly determine what malfunction occurs specifically in your case.

What to do if the microwave does not heat: video

Do you have a microwave but it doesn't work? If you have problems with your microwave oven, use the repair tips to fix the problem yourself. So, the microwave does not heat, but it works: what to do?

Who still doesn’t know that electric current kills? There are two basic rules to avoid fatal electrocution or prolonged treatment in a burn unit:

1. Before you begin any technical intervention on the microwave, disconnect it from the power source, that is, remove the plug from the outlet.
2. When repairing high-voltage systems equipped with energy-storing elements, you must be extremely careful and discharge the capacitor only with tools with well-insulated handles.

Read also:

If you decide to protect yourself with surgical gloves, they will not save you from electric shock. For personal protection, dielectric gloves made of thick rubber have been invented.

We find out the reasons for the breakdown

The Samsung microwave does not heat, but it works - what should I do? It must be said right away that the model of your oven does not matter at all, since almost all microwave ovens are designed the same. As practice shows, if the microwave works but does not heat, this may be the reason:

• Most likely the problem is related to the high voltage circuit;
• problems with the circuit board.

Troubleshooting steps:

• To find the problem, after you have unplugged the microwave, you need to remove the back panel by unscrewing the mounting screws. This will give you access to various elements of the household device. This may not be the case on some models. back panel, and the side or both.
• Don't forget that inside the furnace you may encounter high voltage that builds up in the capacitor, so discharge it safely before starting diagnostics.
• Next, visually assess the extent of possible damage: the presence of burnt elements, melted wires or insulation, etc. If no visible damage is found, move on.
• Go through the chain of high voltage elements, starting from the stove. If it does not heat up, and this process is provided by microwaves, most likely the generator - magnetron - is not working. But this does not mean that it has failed, since there are a number of elements in the high-voltage circuit before it.
• For normal operation of the magnetron, a voltage of 5000 V is needed. It is supplied to it through a transformer, from the secondary winding of which a voltage of 2500 V is removed and doubled using a capacitor. A high-voltage diode is installed at the output of the capacitor to rectify the AC voltage. A high-voltage fuse is installed in the circuit between the transformer and the capacitor, which is equipped with a return-closing spring.

• Disconnect the primary terminals of the high voltage transformer. Using a multimeter with limits set from 100 to 200 ohms, measure the condition of the primary winding. Normal values ​​are in the range of 1-3.5 ohms. To measure the secondary winding, set the ohmmeter limits to 1-2 KOhm. The resistance between the secondary winding output and the power cable grounding point should be between 50-230 Ohms.
• Make the next measurement between the output points of the secondary winding and the connection of the capacitor at the limit of 2 KOhm. If the device shows infinity, it means that the fuse is open and will turn on when voltage is applied after all checks have been carried out. The readings of the multimeter, if the fuse is working, when measuring the resistance between its output and input at the limit of 100-200 Ohms will be in the range of 0.1-2 Ohms.
• Disconnect the magnetron input terminals. Take a measurement between the power terminals, setting the multimeter limit to 100-200 ohms. If the magnetron is working properly, the readings will be between 0.1-0.3 ohms. Infinity will mean a break in the microwave emitter threads.
• The next measurement is the resistance between the magnetron terminals and its body. At the measurement limit of 1-20 KOhm, the device should show isolation, that is, infinity. If a value is displayed, the magnetron will have to be replaced.
• We check the integrity of the capacitor by measuring the resistance between its terminal and the body. If the capacitor is in good working order at the maximum measurement limit, the multimeter should indicate the presence of insulation. There should also be infinity between the terminals of the capacitor.

All that remains is to check the high voltage diode. To do this, we will use a diode tester with a DC voltage of 20 V through a universal controller. The diode must pass current only in the forward direction. If, when the tester is connected to the diode, the indicator lights up in both directions, then it is in a “broken” state and can be safely disposed of. The diode expects the same thing; if the tester indicator does not light up when connected in both the forward and reverse directions, it means that it is “open”.

If the indicator lights up only in the forward direction, this is already good. In parallel with the tester, observing the polarity, we connect the multimeter, having previously set its DC voltage measurement limits to 20 V. If the multimeter shows 7-8 V - great, the diode is working!

We told you, as best we could, what to do when the microwave stopped heating. To wrap up the topic, here are some useful tips:

1. If you have had to change the high-voltage fuse more than twice, then you need to think about replacing the magnetron.
2. Make sure that the permeable mica emitter screen is always clean. A dirty screen does not transmit microwaves well and can cause a plasma arc.
3. Keep the inside of the oven clean so that chips and rust spots do not appear on the protective polymer coating.