In the morning I had to go to work without having breakfast, since cold dumplings or another dish not to everyone's liking. It turns out that the microwave has stopped heating, but it still works. So, why does the microwave break down, what are the causes of the breakdown, how to fix everything with your own hands? Find answers to these questions in this article.
Possible reasons why the microwave oven does not turn off, but it began to heat poorly or does not heat at all are different - due to a power surge or due to insufficient electrical voltage, the mini-switch located in the microwave oven door does not function.
Sometimes the following happens:
- Microwave safety switch burned out;
- The protection element of the high-voltage power circuit is burnt out;
- The fuse on the transformer equipment is out of order;
- Doubler malfunctions - diode;
- The doubler is out of order - the capacitor;
- The transformer does not supply voltage to the microwave control panel.
Problems with the pass-through capacitor are frequent, or a special lamp - a magnetron - does not heat up. When the problem has become clear, it is urgent to fix it. If you have the skills, you can do it yourself. If not, then it is better to contact the service center for help from a professional.
Microwave not working: how to identify the problem
The first step is to carefully study the instructions on how the microwave works, and what needs to be done if the microwave does not warm food. In the instructions, you can find the answer why Samsung microwave ovens (Samsung m1712nr), Scarlet, Sharp (Sharp R2371K) or other models twist and do not heat, what to do in such a situation. Initially, you should measure the voltage of the mains. Even with a small deviation from 220 V, the microwave oven will not warm the food as it should.
- Discharge the household appliance;
- Turn off the microwave oven from the network;
- Check with an ohmmeter how the mini-switch on the stove door turns on;
- Next, remove the cover from the top, unscrew the screws;
- Then it is necessary to check the mains fuse.
If the electrical wire that has burned out inside is not visually noticeable and the fuse has not turned black, then just in case, to be sure, you need to check the resistance with a special tester.
Then you should check the high-voltage fuse in the casing with an ohmmeter, if the device shows a low resistance - it's not so bad. The next step is to check visually and with a tester of the fuse on the transformer - is it normal or not. Next, you can check the components of the multiplier - a diode and a capacitor.
It is possible to check the performance of the capacitor with the device, although it is intended for operation in AC power grids.
The arrow of the device went to infinity, which means that the capacitor first took a small DC charge from the tester, everything is normal. If the capacitor structure is broken, the arrow will not deviate - there is no contact. And if the device immediately shows low resistance, this is bad, it has a hole. Then you need to replace the diode with a new one so as not to check again.
Why the microwave does not turn on: the reasons for the breakdown
The next stage of the check, when the microwave starts up, works by itself, but it cannot heat up as much as it should be. Check the microchannel air-cooled condensers of the filter on the body of a special lamp.
Before checking them, you need to:
- Inspect;
- Discharge with a special screwdriver with an insulated handle;
- In turn, close the leads to the case.
One probe of the device must be placed on the output of the container, the second on the metal case. If the device does not give zero resistance, this is the norm, but if the scale is "0", the part must be replaced.
It is necessary to check the primary winding of the transformer with a special device. When the microwave is turned on, the voltage on the primary winding, when the heating is on, when operating in standby mode (a glass of water put into the oven for 5 minutes), should be 220 V.
Magnetron - the main reason why the microwave stopped heating
A magnetron is a powerful lamp, it itself generates EM waves of frequency (0.5-10 GHz) when the flow of stable negatively charged elementary particles is connected with a magnetic field. But one should not conclude that an urgent repair of a Rollsen microwave oven, Samsung or another brand is needed. Initially, you should visually check the strength of the soldering of the electrical contacts of the filter induction coils and the integrity of the connection of the lamp power supply terminals with the through-feed capacitors.
If the electrical contact has come off or the terminal has oxidized, then it is very easy to repair the stove with your own hands.
Then you need to check with a special device the resistance of the lamp filament, it should be about 2-3 ohms. However, if the check is carried out, and everything seems to be functioning normally, then the magnetron itself is out of order, that is, it does not turn on, the lamp does not shine. Masters do not advise repairing the microwave with their own hands. The body and radiator of a working lamp has a temperature of more than 150 ᵒС. Wait for the lamp to cool completely before touching it with your hands.
- Power;
- Cathode voltage;
- Filament current and voltage;
- Anode current.
You can buy a new 2m214 39f lamp at a service center, then replace it. It is quite possible to fix the microwave if it turns the dishes with food, but does not heat, it is quite possible and on your own, but, as practice has shown, it would be correct to call a repair professional. The master will explain why the microwave oven hums, makes noise, does not heat up weakly or for a long time, and what should be done, find the reason and replace the direct 75232L sources from supply distributors, other components or the lamp itself. After work, he will check whether the lamp turns off and whether the microwave is heating food efficiently.
If the microwave works, but does not heat up, the fuse is to blame
There is another reason for microwave malfunction, in which case the microwave oven seems to function, but does not warm the food. This is the fuse. As already noted, there are 2 of them in the microwave oven system, and if at least one of them deteriorates, the microwave oven will no longer fully function. The solution to the question is quite simple.
You should take a sample (on different microwave ovens, different types of fuses can be used) and find exactly the same in a specialized store, the sales assistant will help you to choose.
The price of the fuse is approximately 30 rubles. Many people today prefer to put in the microwave the so-called "bugs" made in a homemade way. Masters do not recommend such manipulations. First, such experimental designs are dangerous. The probability of fire is extremely high, and you risk losing not only the microwave oven, but also most of the property, and even worse - loved ones, your own life. The second important point is that even if a wire of the correct cross-section is selected, which meets the safety requirements at least a little, not so much 30 rubles. is the cost for a new fuse so high?
No, but the store element is a guarantee:
- Authenticity;
- Security;
- Easy installation.
Masters advise to find, install and be absolutely calm. The main question remains the reason for the failure of the fuse. And even if it is clear why the microwave oven does not heat the food, this is not a fact of eliminating the malfunction. It cannot be ruled out that the fuse has become a symptom of another breakdown. This is not difficult to verify. If everything works fine, but after a couple of days the food does not heat up again, you will have to go to a service center or a specialized store for a new fuse. In addition to non-critical reasons, of course, it may turn out that the microwave does not heat up due to prolonged use or poor quality of components.
The microwave does not heat: the reason (video)
If the problem is complex, and the microwave was purchased recently, it is wise to take it back to the store. It is important to remember that you can “open” household appliances only after the warranty period has expired. Otherwise, the warranty will be void. It should not be forgotten that bold experiments can lead to the complete failure of a beloved and so necessary technique. If a person is not confident in their knowledge and abilities, it would be correct to leave the repair of the microwave oven to specialists. The master will bring the microwave oven back to life in a short time, and will be able to heat food at any time when it is necessary.
Do you have a microwave but it doesn't work? If you are having problems with your microwave oven, use the repair recommendations 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 electric shock or prolonged treatment in a burn unit:
- Before starting technical intervention in the microwave, disconnect it from the power source, that is, pull out the plug from the socket.
- When repairing high voltage systems equipped with energy storage elements, 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 individual protection, dielectric thick rubber gloves 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 arranged the same. As practice shows, if the microwave works, but does not heat, this may be the reason:
- the problem is most likely related to the high voltage circuit;
- faulty circuit board.
Troubleshooting steps:
- To find the fault, after you have disconnected the microwave from the network, you need to remove the back panel by unscrewing the mounting screws. This will give you access to various elements of the household appliance. In some models, this may not be the back panel, but the side panel, or both.
- Remember that inside the oven you may encounter high voltages that build up in the capacitor, so discharge it in a safe way before starting diagnostics.
- Next, visually assess the degree of possible damage: the presence of burnt elements, melted wires or insulation, and the like. If no visible damage is found, move on.
- Go through the high voltage circuit, starting from the stove. If it does not heat up, and this process is provided by microwaves, most likely the generator, the magnetron, does not work. But this does not mean that it has failed, since there are a number of other 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 with a capacitor. A high-voltage diode is installed at the output of the capacitor for rectifying 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 a set range of 100 to 200 ohms, measure the condition of the primary winding. Normal values \u200b\u200bare in the 1-3.5 ohm range. To measure the secondary winding, set the ohmmeter limits of 1-2 KOhm. The resistance between the output of the secondary winding and the grounding point of the power cable must be between 50-230 ohms.
- Take the next measurement between the points of the output of the secondary winding and the connection of the capacitor at the limit of 2 KΩ. If the device shows infinity, then the fuse is open and will turn on when voltage is applied after all the checks. The readings of the multimeter, if the fuse is good, when measuring the resistance between its output and the input at the limit of 100-200 ohms, will be in the range of 0.1-2 ohms.
- Disconnect the input terminals of the magnetron. Measure between the power terminals, setting the multimeter limit to 100-200 ohms. With a working magnetron, the reading will be between 0.1-0.3 ohms. Infinity will mean breakage of the microwaves emitter filaments.
- The next measurement is the resistance between the terminals of the magnetron and its body. At the measurement limit of 1-20 KOhm, the device should show insulation, that is, infinity. If a value is displayed, the magnetron must be replaced.
- We check the integrity of the capacitor by measuring the resistance between its terminal and the case. With a working capacitor at the maximum measurement limit, the multimeter should show the presence of insulation. There should also be infinity between the terminals of the capacitor.
It remains to check the high voltage diode. To do this, we will use a diode tester with a DC voltage of 20 V via a universal controller. The diode must only pass current in the forward direction. If the indicator glows in both directions when the tester is connected to the diode, then it is in a "punctured" state and can be safely disposed of. The same is expected by the diode, if the indicator of the tester does not light when connected both in the forward and in the opposite direction, it means that it is "open circuit".
If the indicator lights up only in the forward direction, that's good. In parallel with the tester, observing the polarity, we connect the multimeter, having previously set the DC voltage measurement limits on it to 20 V. If the multimeter shows 7-8 V - great, the diode is working!
We, as we could, told what to do when the microwave stopped heating. To wrap up the topic, here are some helpful tips:
- If you have had to change the high-voltage fuse more than two times, then you need to think about replacing the magnetron.
- Keep the transparent mica emitter shield clean at all times. A contaminated screen does not transmit microwaves well and may cause a plasma arc.
- Keep the inside of the oven clean so that no chips or rust spots appear on the protective polymer coating.
The microwave oven is one of the most commonly used electrical appliances in the kitchen. Once again, you put food on heating - the microwave hums as usual, the lighting works inside, the plate of food is spinning, but after the time set on the timer the food remains cold. What to do in this case? The failure of the microwave oven causes a number of inconveniences, so many people prefer to try to repair the microwave oven on their own, saving not only time, but also money.
Why doesn't the microwave heat the food? Consider the possible causes of a malfunction of mechanically controlled microwave ovens. We will also give an illustrative example of troubleshooting a microwave oven.
If the microwave oven works, but does not heat the food, then first of all you need to make sure that the voltage in the network is not too low. It is often mistakenly concluded that the microwave is malfunctioning, but in fact the reason lies in the excessively low voltage. Even if the voltage in the electrical network is reduced by 20 V, the microwave oven noticeably loses power and instead of the usual two minutes, it will take 5 or more minutes to heat up food.
If the voltage in the network does not deviate from the permissible limits, then it is necessary to look for a malfunction in the household appliance itself.
A fairly common mistake is that people begin to look for a malfunction without even having an idea, mistakenly believing that when the microwave oven is disconnected from the mains, the danger of electric shock will be excluded.
It must be remembered that the microwave oven is one of the most dangerous household electrical appliances. Even after disconnecting it from the mains, there is a danger of electric shock of several thousand volts, which remains for a long time in the high-voltage capacitor. In the absence of the appropriate knowledge and skills for the repair of electrical appliances, it is better to contact a qualified specialist for service.
The following precautions are always indicated on the microwave oven casing:
If you nevertheless decide to carry out the repair yourself, then all safety measures should be observed when performing troubleshooting work.
Before proceeding with the removal of the microwave housing cover, make sure that the appliance is disconnected from the mains.
A dangerous discharge persists in high-voltage circuits, so you should not rush to check high-voltage elements - as practice shows, most microwave oven faults are located in the primary circuits of 220 V.
Only if a fault in the primary circuits could not be found, then it is necessary to proceed to checking the microwave step-up transformer and high-voltage elements.
Checking electrical circuits before the step-up transformer of the microwave oven
The first step in troubleshooting a microwave oven is to check the electrical circuits and various devices through which voltage is applied to the primary winding of the step-up transformer.
It should be noted that structurally, microwave ovens from different manufacturers have some differences, but in general, the described troubleshooting principle allows you to identify a faulty element in a microwave oven, regardless of its type.
To find a malfunction, you need to remove the microwave housing cover by unscrewing the screws (or screws) on the back of the microwave and on two sides.
Often there are recommendations for checking circuits by applying voltage - that is, turning on the microwave oven. Therefore, testing is not recommended as there is a high risk of electric shock. It is only necessary to turn on the microwave oven with the lid on.
You can check the continuity of the circuits by dialing them with a tester or a multimeter in continuity mode.
If, when the microwave was turned on, the lighting was on, the plate of food was spinning, and the usual noise was heard when the microwave was operating, then the voltage was supplied to the microwave - the power cord is complete, the fuses are not blown, the lighting lamp, the plate rotation motor and the cooling fan are powered.
In this case, first of all, you need to make sure that the voltage of the electrical network falls on the step-up transformer. To do this, remove the terminals from the primary winding of the transformer and proceed to checking the circuits.
In this case, the microwave oven, as mentioned above, must be disconnected from the network. Before dialing, turn on the microwave cooking mode (the grill mode switches the power to the heating elements, while the transformer is de-energized), the microwave oven timer and close the microwave door so that the door lock limit switches close.
In the absence of an open circuit and faults in other elements, the continuity should show the continuity of the circuit between the phase terminal at the input from the power cord and one of the removed terminals of the step-down transformer, as well as the continuity of the circuit between the zero input from the power cord to the second terminal supplying the transformer.
If the device shows a break, then you need to find out where it is. To do this, it is necessary to ring all the elements and circuits that go to the terminals of the primary winding of the transformer.
On the case or in the instructions for use of the microwave oven, a schematic electrical diagram of this electrical appliance can be given. The presence of the circuit simplifies the troubleshooting process. In the absence of a circuit, it is necessary to carry out a continuity, visually tracing the path of current flow to each element, starting from the very beginning - from the power filter board, where the phase and neutral conductors of the microwave oven power cord are connected.
If the microwave oven has an additional grill function, then when the chains are ringing, these circuits should be excluded, in this case we are interested in the circuits of the microwave itself.
You need to ring the circuits from the power board to the microwave oven electromechanical control unit. If voltage is not supplied to this unit, then it is necessary to check all circuits through which current flows to this element.
From the power filter board, the conductors go to a thermal relay (thermal fuse). This element is triggered if the magnetron overheats during continuous operation of the microwave oven at full power.
If there was no overheating, but the thermal fuse is in a triggered state, then this indicates its malfunction - this element must be replaced.
If, when the door is closed, one of the limit switches does not close, then the reason for this may be a loose door closing. To eliminate this malfunction, tighten the fasteners and latches of the door, ensuring that it is tightly closed. It is also possible that one of the switches may be damaged, in which case they must be replaced.
If the circuits supplying voltage to the control unit are complete, then we are looking for the reason for the inoperability of the microwave oven further - we check the unit itself.
The electromechanical control unit is used to switch the operating modes of the microwave oven, turn on the timer. It contains several contacts that ensure the operation of the microwave in one mode or another.
In order to check the performance of the control unit, it is necessary to find the terminal to which the voltage comes from the mains and the terminal through which the voltage is supplied to the step-up transformer. Next, you need to turn on the microwave and the timer. In this case, the device should show the continuity of the circuit between the indicated terminals.
If there is no contact between the terminals, then this indicates a malfunction inside the electromechanical control unit.
Before removing the control unit, you must record which wire (wire color) is connected to each of the terminals. All pins on the block are numbered. This is necessary in order to prevent errors in connecting microwave circuits when installing the control unit in the future.
Also, to remove the control unit, it is necessary to remove the switch knobs on the front panel. After removing the handles, it will not be clear where which mode is, therefore, you must immediately set the timer to the off position, and the operating mode to high microwave power. After removing the handles from the inside of the control unit, unscrew the three screws, after which the unit can be removed from the microwave housing.
Next, we put marks with a marker on all moving elements and a corresponding mark on the body of the control unit - these marks will help to avoid mistakes when assembling the mechanism. We unscrew the three screws (1), remove the upper part of the control unit - in front of us is the part of the unit, which contains the contacts (2).
We unscrew one screw and remove the top cover of this unit.
We see that contacts 2 and 3 are in a normal state, and contact 1 is burned, when the timer is turned on, this contact should close, but it does not close. The reason for the violation of the contact was a decrease in the rigidity of the contacting plates, as well as their displacement relative to each other, as a result of which the contacting surfaces touched very weakly. The contact sparked under load, which ultimately led to a complete breakdown of contact.
In this case, troubleshooting is quite simple. The contacting surfaces must be well cleaned and bent so that when the timer is turned on, the contacting plates touch firmly and do not move relative to each other. At the same time, the plates should not touch when the timer is off.
If the contacts are badly burnt and the body of the control unit is deformed under the influence of heated contacts, then it is better to replace such a unit with a new one.
Checking the integrity of the step-up transformer windings
If the circuits to the primary winding of the microwave step-up transformer are complete, that is, the voltage is supplied to the step-up transformer, but the microwave does not heat the food, then a possible cause may be damage to one of the transformer windings.
The integrity check of the windings is carried out. To measure the resistance, you must remove the terminals from both windings. One terminal is removed from the secondary winding, since the second terminal is shorted to the transformer housing and, accordingly, the microwave oven, since it is screwed to it without surface insulation. The filament winding is checked after removing the terminals from the magnetron.
When removing the terminal from the secondary and filament windings, it is necessary to remember the danger of electric shock from the residual charge of the high-voltage capacitor, which was mentioned at the beginning of the article. If the high-voltage capacitor is not discharged, then the terminals from the secondary winding must be removed using a tool with insulating handles - pliers and a screwdriver.
We measure the resistance of the primary winding by setting the measurement limit on the multimeter to 200 Ohm (or within this value, depending on the type of measuring device). The normal resistance of the primary winding is 2-5 ohms.
At the same measurement limit, it is necessary to check the integrity of the filament winding, the leads of which go to the magnetron. One of the leads goes directly to the magnetron, and the second lead goes to the high-voltage capacitor terminal and from the same terminal to the magnetron, that is, to check the winding, you do not need to remove the terminal from the capacitor, it is enough to remove two terminals from the magnetron leads. The permissible resistance of this winding is 3-8 ohms.
We switch the measurement limit to 2 kΩ and measure the resistance of the secondary winding between the terminal on the transformer itself and any place cleaned to metal on the microwave oven case. The admissible resistance of the secondary winding is in the range of 140-350 Ohm.
If the resistance of one of the windings is above the permissible limits, then this indicates a break in the winding, and if the resistance is below the permissible limit, then this indicates the presence of an interturn short circuit in this winding.
The primary symptoms of a microwave oven step-up transformer are;
the presence of extraneous noise, crackling, not typical for the normal operation of the appliance;
the smell of burning from the microwave body;
strong heating of the transformer;
blackening, melting of the insulating materials of the windings.
The defective transformer must be replaced with a new one of appropriate capacity. To dismantle the transformer, unscrew the 4 screws located under the microwave oven housing.
Before replacing the transformer, it is necessary to check the health of the high-voltage elements, since there is a high probability that the failure of the transformer was caused by damage to one of the elements in the high-voltage circuit. Also, high-voltage circuits are checked if the circuits to the transformer are complete and the transformer itself is in good condition.
First of all, it is necessary to visually check the integrity of all high-voltage circuits, the reliability of the terminals on the terminals of the fuse, capacitor, diode and magnetron.
The high voltage fuse (see photo above) is checked for continuity by dialing.
The magnetron is tested with a multimeter in resistance measurement mode. With the terminals removed, it is checked by the resistance between the terminals of the magnetron at the lowest resistance measurement limit. If the magnetron is in good working order, it should show low resistance, up to 1 Ohm. The resistance of each lead relative to the magnetron body is also checked - it must be very large, several megohms.
The magnetron structurally has a pass-through capacitor, therefore, when checking the health of the magnetron, the capacitance of each of the terminals of the magnetron relative to the case is also checked. Without a special device, it will not work to measure the capacity.
The same goes for the high voltage capacitor. It will not be possible to check this element without a special device.
Therefore, it is necessary to focus only on the primary signs of damage to the capacitor, magnetron - the presence of extraneous sounds that are not typical for the normal operation of the microwave, swelling of the condenser, the smell of burning.
The high-voltage diode cannot be checked with an ordinary multimeter. One of the options for testing a high-voltage diode is to test it with a conventional incandescent lamp. This method is quite dangerous, since careless handling of electricity can get you an electric shock.
It is better to leave the diode check for last - when all the elements have already been checked, and the malfunction has not been detected. Or purchase a new high-voltage diode that is guaranteed to be in good working order.
If it is nevertheless necessary to check the diode, then this element is checked by an incandescent lamp as follows. The socket from the incandescent lamp is connected to the plug to be connected to the network, a high-voltage diode is turned on in the break of one of the conductors, the lamp is turned on. Both with direct and reverse switching on of a working diode, the lamp should burn at half the incandescence and flicker noticeably.
Andrey Povny
Most city dwellers are so accustomed to the convenience of using a microwave oven that it is impossible to imagine a kitchen without this useful device.
If the microwave stops heating, this is a small tragedy: everyone starts to be late for work or school, the dishes that have become habitual disappear from the table. It is not necessary to immediately call the master. Most faults can be repaired, and some problems can be completely eliminated on their own. To deal with breakdowns, you need to understand how the device functions.
Information: A microwave oven and a microwave oven are one and the same household appliance.
The principle of operation of the microwave oven
There are many designs of microwave ovens, which differ in design options, but not in the principle of operation. It is based on the effect of super-high-frequency (microwave) fields on conductive matter. Take a piece of raw meat, for example. It contains enough moisture to become a full-fledged conductor of electric current. Under the influence of microwave waves, the meat particles begin to vibrate finely but intensely and rub against each other. This phenomenon is invisible to the eye, however, it leads to strong heating of the material. To the extent that raw food becomes boiled (baked, stewed), it is difficult to come up with a name for the cooking process.
Unlike a skillet, pressure cooker, or oven, a microwave does not heat food. It creates conditions for raising the temperature inside the semi-finished product. As a result, the food is cooked simultaneously in the whole mass, and not from the crust to the center.
How is this implemented in practice?
The illustration shows a typical microwave oven, we will tell you about the nuances of other designs in the description.
- As in any electrical installation, it all starts with the power supply. Its basis is a high-frequency transformer (1), which generates high-frequency alternating current.
- It powers the magnetron (2): the heart of the microwave. It is this device that emits the very same microwave waves, which many are unfairly afraid of, and which heat food in the chamber.
- The waves are radiated in a directional way, they must be "driven" into the cooking chamber. There are two ways: waveguide (3), as in our example, or direct radiation into the housing. Both options have advantages and disadvantages, there is no point in discussing them.
- Further, these same waves (6) must be evenly distributed over the entire volume of the semi-finished product (7). To do this, you can rotate a tray with food (most microwave ovens are designed this way), or set a variable direction using a wave splitter (5). In any case, an electric motor is needed (4).
- Another must-have is the cooling fan. It cools the magnetron, which gets very hot during this operation.
Information: It is the operation of the fan (and not the motor that rotates the tray) that we hear during the operation of the microwave.
At first glance, repairing a microwave oven with your own hands is not such a difficult task. There are not many elements that cannot be repaired, they can be replaced. This is partly true. For a home craftsman familiar with the radio business, repair and maintenance of microwave ovens with his own hands is possible. The main thing is not to lose the warranty from the equipment seller.
The basic elements do not cause problems. But the electronic control module can be so complex that the rest of the malfunctions of the microwave oven will hardly outweigh its breakdown. The illustration shows only the Samsung microwave oven controller.
For comparison, let's take a look at a simpler design. This circuit has everything: the basic elements, and the power supply, and the control board for the entire furnace.
Problems that are not malfunctions but block operation
It is important to know: if the microwave does not work, the reason is not necessarily a malfunction. Many of you have seen videos on Youtube with ridiculous and sometimes dangerous experiments on microwave ovens. The fact is that this useful unit can be dangerous to human health (and pets) if used incorrectly. Therefore, manufacturers build into the equipment various protective elements that block the start of the magnetron under certain conditions. So, if your microwave does not heat, but there are no obvious signs of a malfunction, one of the protective fuses may have worked.
Information: The microwave oven is not a source of radioactive radiation. Everything that this device generates is high-frequency electromagnetic waves. They are really harmful to a living organism, but only if they come under their direct influence.
Real microwave oven malfunctions and solutions
If you correctly connect and use the microwave oven, but it still does not work, then you will have to look for a breakdown and repair it (if possible on your own).
Outcome
Simple microwave ovens are inexpensive. But this does not mean that in case of a breakdown, you need to buy a new unit. A little patience, basic knowledge of electrical engineering, and you can restore the microwave oven yourself.
Related Videos
Sometimes you may find that a microwave oven that has been working until recently works but does not heat up, and we take out a cold dish. There are many reasons for this, and among them there are both serious breakdowns and minor malfunctions that can be easily eliminated by hand. Today we will consider what to do if the microwave does not heat up and we will analyze how to solve this problem.
Self-repair features
If you notice that the food remains cold even after a few minutes in the oven, then this certainly indicates a malfunction of the appliance. The reason that the microwave turns but does not heat may be as follows:
| Photo | Description |
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Reason 1
Incorrectly set mode. For example, the “Defrost” function cannot fully heat food. |
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Reason 2
Insufficient voltage. Sometimes drops of several volts can affect the operation of equipment. |
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Reason 3
Broken door latches and loose fit to the furnace body. |
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Reason 4
The high voltage fuse, mains fuse or transformer fuse has blown and must be replaced. |
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Reason 5
Failure of the multiplier, which consists of two dependent elements (high-voltage diode and capacitor). |
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Reason 6
Breakdown of the in-line capacitor. |
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Reason 7
The magnetron and the electromagnetic lamp are out of order. |
Careful operation is the key to long and trouble-free operation of the oven. Perhaps the reason that the microwave stopped heating was the accidental hit of a metal device or foil into the chamber. Do not reheat food together with cutlery, in metal dishes, dishes with metallized film edges and in foil containers!
Troubleshooting minor issues: 3 solutions
Most of the above reasons why the microwave does not heat up can be eliminated on your own, saving a lot on the services of service centers. For this we only need a screwdriver and instruments for measuring resistance and voltage.
The instruction manual and user manual are the primary documents that you should refer to when troubleshooting. Often, the manufacturer indicates useful information for the correct diagnosis of malfunctions and their possible elimination with their own hands.
Possible minor malfunctions of microwave ovens and how to fix them:
| Photo | Description |
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Solution 1. Wrong mode
Make sure the control panel is set to the correct mode (warm-up function).
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Solution 2. Insufficient voltage
The oven does not heat food if the home voltage is low:
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Solution 3: door malfunction
Often the door in microwave ovens does not close tightly, and sometimes the latches themselves fail, which in turn start the magnetron. Decision: replace the latches and close the door tightly. |
Troubleshooting serious faults: 4 solutions
In other cases, as well as if the microwave is humming but does not heat up, you should contact a specialist. Repair and replacement of parts under warranty will be free, but in case of an expired warranty period, you will have to pay for the repair from your pocket.
The price, as a rule, consists of the cost of the new part and the services of the master. But you can save a little in this case too by replacing the defective part yourself.
The table below and illustrative photos will help you cope with the task:
| Photo | Description |
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Solution 1. Blown fuse (one or more)
In this case, the microwave oven will no longer have the above problems. |
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Solution 2. Broken multiplier
The multiplier capacitor must be checked. To do this, you need an ohmmeter:
Failure of this part is often the reason why the microwave does not heat, but works. It is worth checking the diode itself. In any case, it is easier and cheaper to purchase a new part than to repair an old one. |
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Solution 3. Faulty feed-through capacitors of the EM lamp
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Solution 4. Broken magnetron or electromagnetic lamp
A malfunction of the magnetron can be the reason that the microwave works - but does not heat: In more than half of the cases, the filament in the magnetron is faulty. To correct the situation, simply measure the resistances to diagnose the malfunction. However, it is easier and simpler to purchase a new magnetron, while it is important to write down all the characteristics and, just in case, take the old part with you. |
Do not expect a long and trouble-free service from cheap devices or microwave ovens from little-known manufacturers. Suppose you spend more, but a high-quality branded microwave oven works for a long time, and in case of repair, there is no problem finding a replacement part.
Conclusion
We have analyzed the most common reasons why the microwave stops heating food, although otherwise it functions quite well. Often a problem of this kind can be corrected on your own: you just need to understand the instructions and in case of malfunctions, replace the failed part.
The video in this article tells and clearly shows possible options for solving problems with microwave ovens. If you have any questions, I will answer them in the comments.