The microwave works, but does not heat - reasons for how to repair it yourself

A microwave oven is an indispensable assistant in almost any kitchen. Its failure is a very annoying nuisance.

Sometimes the equipment behaves completely strangely: it turns on, works, the light is on inside the chamber, but the food is poorly heated or even turns out to be cold. Why does the microwave work but not heat?

The reasons are varied - from simple ones that can be eliminated on your own, to serious ones. We will tell you what to do and what to pay attention to in such cases in a detailed guide.

The same instructions included recommendations from appliance repair specialists and advice from professionals.

How does a microwave oven work?

To repair/maintain any equipment, including a microwave oven, you need to know the principle of its operation. Let's look at the basic elements and their purpose.

Magnetron

At the heart of a microwave oven is a magnetron, which, when turned on, produces microwave energy and distributes it throughout the interior.

The magnetron screen is located inside the microwave on the right behind the wall where the control panel is located. It is made in the form of a cover, which is attached to latches or screws.

The function of the screen is to protect the magnetron from particles of food from the cooking zone.

The device is connected to the camera using a rectangular waveguide, which is covered with a glass or plastic cover.

Power supply

Transformers-stabilizers, which are the most complex and expensive element, act as a power source.

As additional equipment, a multiplier is used, which includes a capacitance and a diode bridge.

After applying voltage to the magnetron, the fan also turns on, which distributes warm air and thereby speeds up the cooking process.

Frame

The microwave has a rectangular body, which is key when heating.

The heat and waves generated during operation are reflected from surfaces and distributed evenly inside.

An additional advantage is the rotation of the saucer on which the food is placed. This function is provided by a special motor.

Control Panel

The microwave oven is configured using the control panel.

Depending on the complexity of the equipment, it can be mechanical (rotating handles) or touch (buttons).

Additionally, a number of protections are provided to ensure safe operation.

For example, when the door is opened, the oven automatically stops working. There is also a timer that turns off after a certain time.

Door

When making a microwave oven, special attention is paid to the door. The gap between it and the body should be minimal.

An HF choke valve is installed along the perimeter, acting as a barrier to dangerous waves.

In addition, plastic that can absorb radiation is used in manufacturing.

About security

Contrary to popular belief, a microwave does not emit radioactive waves, so when heated, at least 75% of the nutrients in food are retained.

Useful tips

In order not to waste time determining the reason why the Daewoo microwave stopped heating, you need to adhere to the basic rules for operating the equipment:

• toxic cleaning powders can get into food or damage the magnetron;
• dirt and grease from the body can be removed with a damp cloth;
• to remove dirt from the door, use a damp sponge and wipe the insulation;
• It is advisable to wipe touch panels with dry wipes;
• to get rid of an unpleasant odor, heat a glass of water with a slice of lemon;
• Reheat food by covering it with a special plastic lid to keep the walls of the heat chamber clean.

If the enamel inside the microwave has peeled off, be sure to paint over the damaged areas.

Reasons why the microwave does not heat, but works

Experts identify many reasons why a microwave may work, but not perform basic heating functions. Conventionally, all reasons are divided into the most common, simple and complex.

To avoid confusion, we will consider them separately.

Common faults

First, let's highlight the most common explanations for the fact that the microwave oven does not perform its functions:

1. Heating food with metal elements: spoon, fork, etc.
2. Using unsuitable utensils: metal, gold-rimmed, lidded, etc.
3. Low quality equipment and rapid failure. Many manufacturers do not bother with high quality parts so that customers go for new products.
4. Natural aging of microwave elements, etc.

Simple causes and tips for eliminating them

There are many simple faults that cause a microwave oven to malfunction.

Let's highlight the main ones:

If the options considered are checked, but the device still does not work, there is a serious malfunction.

In this case, it is necessary to conduct additional diagnostics.

Checking feed-through capacitors

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.

Complex malfunctions, the microwave heats up but makes a humming sound

In more complex cases, we are talking about some kind of equipment malfunction. After turning on, the tray rotates, the light is on, but the microwave oven does not heat anything. There may be several reasons for this.

Control block

To determine whether the control unit is faulty, it is important to have some experience. In the absence of one, it is better not to meddle with this mechanism due to the risk of damaging expensive elements.

For beginners, the best way is to replace the equipment or update its firmware.

Magnetron

The most difficult situation is when the microwave does not work due to damage to the magnetron.

The malfunction of this part may be due to the following reasons:

1. Poor contact connection. If the contact weakens, heating occurs at the connection point, which leads to the impossibility of normal operation. To fix the problem, you need to compress the contact group using pliers.
2. Deterioration of the metal. Many microwave ovens have a hole in the cap through which you can look at the metal elements and evaluate their condition. If the metal is intact, the problem is in the cap, which requires replacement. If the metal is damaged, the microwave may break. The solution to the problem is to replace the magnetron, which is expensive, or to buy a new microwave oven.
3. Traces of burnt or metal drops on the surface. To remove them, use sandpaper to clean the cap and thus improve its conductivity.

Fuse

In a situation where the microwave does not work, check the integrity of any fuses that may have blown. Externally, such elements look like a glass flask with metal inserts inside.

There are caps installed on the sides, to which a wire in the form of a spring is connected.

The current passes through the fuse and if this parameter exceeds the optimal norm, the insert burns out.

There is also a situation when the wire simply comes off, which is why the voltage does not flow into the microwave oven.

Mica plate (magnetron screen)

A special plate is installed inside the heating zone, which can be inspected visually and identify a malfunction.

With prolonged use and lack of proper care, soot may appear on this element and a thick layer of fat may accumulate. This dirt interferes with the normal operation of the element and causes the microwave oven to not work.

In addition, contamination may cause sparking or cracking noises. In the most difficult cases, the part may even catch fire.

Capacitor, transformer

If the microwave oven does not heat food and makes a lot of noise, in 90% of cases the cause is a burnt-out capacitor.

If smoke appears after turning on the device, this indicates damage to the transformer.

A malfunction can be indicated by normal overheating without damage to the part.

Diode

A broken diode can lead to heating and damage to the capacitor.

Diagnosing such a malfunction is a complex process, so replacement is carried out even if a breakdown is suspected.

Inverter

The purpose of the device is to determine the temperature inside the chamber and the products themselves.

Control is carried out using sensors that can fail or provide incorrect information.

In both cases, the microwave oven simply will not heat the food.

Timer

If damaged, the timer does not work correctly and begins to randomly turn on and off the equipment.

It makes no sense to repair this part, so the only correct solution is replacement.

We are looking for a technical reason

If the microwave oven is inspected and you do not find anything preventing rotation, you will have to look for technical problems. Most likely, the microwave oven will need repairs, the complexity of which is again determined by the source of the breakdown.

It is logical to assume that the stoppage of movement is due to a malfunction of the torque mechanism. But the problem can be caused by even such a trifle as a burnt-out interior light bulb - this is what owners of older generation microwaves face. Look for problems that led to the stop in the following components and parts:

Gear. A broken gearbox is one of the most common causes of a pallet stall. Replace it. If this does not help, you will need serious and expensive repairs - replacing the engine. Considering the cost of such repairs, it is cheaper to recycle the old device and buy a new one. This way you won’t have to spend money on repairs; you will purchase a new, more reliable and functional model from a reliable manufacturer.

• Clutch. This connecting mechanism, slipping on the shaft, can interfere with rotation. Try to strengthen it by eliminating slippage. Did not help? Then you need to change the clutch.
• Motor winding. If it is torn, professional intervention will be needed. The winding cannot be restored; it needs to be replaced. You can radically solve the problem - change the motor. You can find out about damage to the winding without disassembling the equipment - the smell of burnt varnish appears.
• Power circuit. To check the integrity of the power circuit, test the wiring with a tester. Did you find an open circuit? You just need to eliminate it.

Diagnostics and troubleshooting

Before carrying out repair work, it is important to carry out diagnostics to determine the malfunction.

In a situation where the microwave does not work, turns on every once in a while, hums or does not heat, but works, do the following:

1. Check the voltage supplied to the transformer. To do this, use a regular multimeter and follow safety precautions. If the voltage drops below 215 Volts, connect a stabilizer or wait until this parameter normalizes.
2. Check that the door latch is working properly.
3. Make sure that the contact connections are reliable, as well as the serviceability of the main elements.
4. Disconnect the microwave oven from the power supply and remove the upper part of the housing.
5. Remove the chip from the magnetron and check it.
6. Place the magnetron terminals in place.
7. Check the capacitor.
8. Check diodes.
9. Check the integrity of the fuses. Burnt-out elements are immediately visible by blackening.
10. If the latter burns out, check the multiplier nodes.

We will consider the features of checking each of the above elements in a separate section below.

After identifying the malfunction, you can decide whether to repair the microwave oven.

If there is a crackling sound, do the following:

1. Determine which part the cracking is coming from.
2. Turn off the power.
3. Remove the mica plate and replace it (costs about two dollars) if it is burnt.
4. Unscrew the magnetron, which is attached to 2-4 screws.
5. Remove the cap that is located at the outlet. If it is tight, loosen it and remove it by hand.
6. Look at the metal outlet under the cap to see if there is a breakdown. If such traces are present, the magnetron must be replaced.
7. If the feed-through capacitors fail, they must be replaced.
8. If the cap is burnt out, replace it.
9. Replace the capacitor if it is the one that fails.

How to detect problems with a microwave oven?

If you decide to find out for yourself why the microwave stopped heating, then it is best to follow simple instructions:

• Check the voltage at the outlet - even small deviations from normal values ​​affect the quality of heating food.
• Check how well the door latches work.
• Turn off the power to the device and remove the top cover.
• Inspect the fuses: if these elements are damaged, you will immediately notice that they will be swollen and blackened. If there is no damage, then you can check it with a tester.
• Using an ohmmeter, check the diodes and capacitors.
• As soon as the stove has cooled down, inspect the magnetron and the contacts leading to it, check the resistance.

Repair rules

Unqualified repairs often lead to negative consequences in the form of health problems or worsening microwave malfunctions.

To eliminate such moments, follow these rules:

1. Always relieve tension before carrying out repair work. To do this, remove the cord from the outlet.
2. Use protective gloves made of dielectric material that can protect against voltages up to 1000 V.
3. Perform repairs/diagnosis using tools that have insulated handles.
4. Do not apply voltage to the microwave after parts have been removed, without food, with the door open, or if there is a suspected malfunction.
5. Discharge the capacitor before checking, removing or replacing. For this
6. Be careful and check the microwave oven for metal objects inside after repair. ATTENTION: It is normal for a spark to jump between the housing and the capacitor.
7. Do not drill holes in the case, as this may damage the device.

conclusions

A microwave oven is considered one of the most dangerous household appliances because it contains very high electrical voltage (up to 5000 V). Therefore, you need to be very careful when performing repairs on this device yourself. If you do not have certain knowledge in the field of electronics and skills, you should not undertake the correction at all.

The most correct decision is to seek help from a qualified specialist with extensive experience. Firstly, it will save time, and secondly, it will save the family budget. As practice shows, 80% of devices after self-repair end up in the hands of craftsmen, because they very quickly fail again. Therefore, to avoid double fees, it is better to contact the workshop immediately.

Features of repairing models from different manufacturers

Despite the similarity in design and operating principle, each manufacturer uses its own secrets in the manufacture of equipment.

Taking this into account, you need to take an individual approach to repairs and pay attention to the manufacturer’s brand.

Below we will consider the features for each of the options and summarize them in a table.

Let's sum it up

A microwave oven is a necessary household appliance for any home. But to ensure it works smoothly and your food doesn’t stay cold, you need to keep an eye on it. It is better to wipe off any drops of fat that fall on the walls of the chamber immediately, and do a full wash at least once a week. This will prevent burnout of the mica plate, as well as failure of the magnetron.

Plates with a silver or gold pattern are direct damage to the equipment, this should also be remembered. The dishes should match the size of the rotating tray or be slightly smaller - this will protect against scratches on the walls of the chamber. By following these simple rules, you will extend the life of your microwave oven for many years.

Take care of your equipment - this will extend its service life for many years. We hope that the information presented in today's article was useful to our dear reader. Despite the fact that we tried to present it in the most accessible way, perhaps some of you still have unclear points or have questions while reading. Describe the point in the discussions below.

Our editorial team will try to answer all questions and clarify unclear points as quickly and thoroughly as possible. Have you ever had a problem with your microwave that you solved on your own? Write about it - such experience will be useful for beginning home craftsmen. Ask, communicate, share opinions. And finally, we suggest watching a video about repairing microwave ovens with your own hands.

How much does the repair cost?

If you lack experience, it is better to entrust microwave oven repair to specialists. Depending on the policy of the service center and the complexity of the malfunction, the cost of work may vary.

For example, for a simple repair you will have to pay from 1000 rubles, for work of average complexity - from 3000 rubles, and for solving a complex problem - from 6000 rubles. (at the end of 2022).

Common breakdowns:

1. Buttons do not work due to damage to the control panel - from 2600 RUR.
2. Malfunction of the magnetron, capacitor - from 2550 rubles.
3. Replacement of a fuse due to blown during a power surge - from 2600 RUR;
4. Sparking in the device - from 3150 rub.
5. The start button on the microwave oven (control unit) is not pressed - from 2900 RUR.
6. Damage to the heating element - from 3200 rub.
7. Door malfunction - from 2650 RUR.
8. Breakdown of the motor for rotating the plate - from 2550 rubles.
9. The device does not turn off (timer, switch) - from 2650 rub.
10. Microwave oven does not turn on (electrical circuit) - from 2900 rub.

The exact price is determined individually after diagnostics and determination of the malfunction.

Other possible malfunctions: causes, solutions

It happens that heating is produced, the light inside the chamber lights up, but the platform does not rotate. The reasons for this may be:

• incorrect installation of the plate;
• broken drive gears;
• engine failure;
• bad contacts.

The problem with the plate is easily solved - you just need to fix it. If this is not the reason, you will have to disassemble the device. Failure of gear gears is a problem that occurs more often in new models of microwave ovens.

In pursuit of reducing the cost of the product, the manufacturer began installing short-lived plastic gears (older models had metal ones). If this is the reason, then the sore is treated by replacing the gearbox - restoring the gear teeth is unrealistic.

The plate must fit neatly into the grooves. The gear motor that rotates the tray may fail under the influence of power surges. In this case, one of the stator windings burns out. The result is motor failure.

Previously, engines could be sent in for repairs. They were rewound and they could function again. Today, such workshops no longer exist: in the event of such a breakdown, you will have to buy and install a new one. The main thing is to clearly and correctly rewrite the markings. Otherwise, the engine simply will not fit your model. The solution to the problem of bad contacts is quite simple. All connections must be cleaned of oxide, if necessary, tightened and connected in the reverse order.

What to do if the microwave oven does not turn on at all

If the microwave does not turn on, the reasons should be sought in the 220 V socket, plug, wire or fuse. The socket is checked, the wire and fuse are checked using a multimeter. The faulty part is replaced with a new one. If you think about it, this is the simplest problem that can happen to your microwave oven.

A blown microwave oven fuse needs to be replaced.

Prevention of breakdowns

To protect your microwave oven from damage and extend its service life, you must follow a number of simple rules:

1. Heat food only in the “correct” containers, which are recommended for use in a microwave oven. It is prohibited to use metal containers or utensils with metal, silver or gold plating. Otherwise, there is a high risk of the equipment catching fire.
2. Do not place anything on top of the microwave.
3. Do not cover food containers completely while heating. This is important for steam release.
4. Do not use carriers to connect.
5. Do not drink alcoholic beverages.
6. Do not boil/heat eggs or other foods that are restricted by the microwave manufacturer.
7. Cover food with a special cap to protect the inner surface from grease. This simple rule can significantly extend the service life of the product.
8. Install the microwave oven taking into account the manufacturer's recommendations.
9. Do not turn on the microwave without food inside.
10. When cooking vegetables, make cuts to allow the internal juices to escape.
11. Close the doors carefully to prevent damage to the latch and other parts.
12. Constantly clean the microwave from grease and food debris, especially pay attention to the magnetron screen. Dirt accumulated on it leads to sparking and the appearance of extraneous noise.

If possible, use heat-resistant dishes made from special glass.

Its features include the ability to evenly distribute heat, which allows you to cook food faster and avoid consequences.

It is better to use a transparent and oval container for heating/cooking. Alternatively, you can use porcelain, glass, special plastic or ceramic dishes.

Why problems might arise

The microwave is working but the food is not heating, it will be important for you to know that certain factors are often the cause:

1. Difficulties arising with the supply voltage: to eliminate the cause, it is worth purchasing a power supply of the specified power.
2. Failure of parts - over time, the design stops working correctly, the door does not open well and the dishes do not warm up completely.
3. Setting the random mode.
4. Presence of unnecessary objects in the chamber.

Constantly monitor the serviceability of the selected microwave oven.

To determine the reasons why the microwave does not heat and is noisy, carry out a comprehensive diagnosis. Start with a visual inspection of the walls of the heat chamber and the power cable. If the microwave does not heat, you need to disassemble the device to check the functionality of the components.

It is important to know that problems in the proper operation of a microwave often lie in its careless use, violation of basic rules and recommendations. As a rule, it is mainly very cheap models that become faulty; their parts wear out quite quickly and easily. Remember that it is the users themselves who are to blame if the microwave oven refuses to heat food properly.

Pay attention to some important points: the fuse has a glass bulb and metal elements. When you see a break in the chain, you need to replace it immediately.

Difficulties with the magnetron - poor quality and untested contacts (due to constant heating). The solution to this problem is simple - restoring contact using special tools. Has the cap turned black? You have to make an effort to clean it carefully. The antenna cap is damaged - carefully inspect the magnetron itself, make sure the element is in good condition. Replace the cap, and, if necessary, the magnetron: the new parts must match the installed ones in terms of power and structural features.

To prevent equipment from being used with the door poorly closed, special small switches are installed. It is important to know that often the reason why a microwave does not heat can be due to defects in the microswitch. This will require urgent replacement of parts.

Always be careful about the rules for using the selected devices. If necessary, contact trained specialists and experienced craftsmen.