Repair of inverter microwave. We repair the microwave oven with our own hands without services. Typical mechanical and electronic failures

Microwave oven Panasonic NN-G335 is a very successful model, both in design and functionality. Until now, this model has not been discontinued, but has only undergone a slight restyling. The oven has an exceptionally convenient door opening handle, is equipped with a grill and electronic (touch) controls. Despite the relatively high price in its class, the Panasonic NN-G335 microwave oven is in great demand among buyers. What is the furnace like in operation in terms of the reliability of electronic and mechanical components?

Let us consider in order all the malfunctions that the author of the article has encountered with this microwave from the moment of purchase (2006) to this day.
The first thing that immediately begins to irritate is the too loud signal from the speaker. I just want to take the stove apart to seal the sound hole. But you soon get used to it and, sometimes, you even want to praise the microwave developers for the range of the signal that the dish is ready, which can be heard even with music turned on in the room.
The main unpleasant moment in operation is that the bottom of the oven chamber is prone to corrosion (rusting) in the place where the plastic wheels of the turntable run.

Rusted bottom of the chamber.

After about three years of operation, through corrosion of the chamber bottom formed. The corrosion was probably caused by high humidity and friction of the turntable wheels. Immediately after such a chamber defect was discovered, the oven was checked for radiation leakage using a microwave detector. Everything turned out to be normal. The outer casing provides good shielding despite the major destruction of the camera.
During the second year of operation, the camera backlight lamp burned out. The breakdown is not at all terrible and can be easily repaired. You need to: open the oven (remove the cover), disconnect the wires on the lamp, remove the lamp and install a new one. However, the lamp used there is not an ordinary one, but a special one for microwave ovens (the base is not threaded, but in the form of two contacts). Buying a lamp is not particularly problematic. As a last resort, you can install a regular lamp, coming up with a way to attach it and connect the power wires.

Backlight lamp.
Shines through small through holes directly into the camera .

In the third year of operation, at one “wonderful” moment the stove refused to work at all (the display did not light up, there were no signs of life). After opening the case, the thermostats were checked first, and a malfunction was immediately found - one of the thermostats was in a constantly open state. There are two such thermostats in the Panasonic NN-G335 oven, both of which open when their housing heats up above the nominal response temperature (indicated on the thermostat housing). In order to replace a failed thermostat in any microwave oven, you need to know the response temperature of the failed thermostat, its operating switching current, the type of switching (on or off) and the type of housing (appearance). It was not possible to find a thermostat that matches the mounting brackets. This is not scary, the main thing is to ensure reliable thermal contact of the thermostat housing with the body of the object under study (the structural part of the furnace on which it is installed).

"Live" thermostat in standard installation (photo on the left).
Replaced thermostat. Installed using an additional pressure plate and self-tapping screws (photo on the right).

It is difficult to say what was the reason for the thermostat failure. Most likely, the reason is simply time, because everything has its own service life. If overheating had occurred, for example, due to something blocking the external ventilation slots, then after turning off the stove and cooling it down, a working thermostat should turn on again, which did not happen.
And the last thing we had to deal with was the blowing of the power supply fuse as a result of the protection diode tripping.

Blown fuse (8 A).

Power board with removed blown fuse F1 (photo on the left).
Power board, view of the speaker (buzzer).The hole marked with a red circle can be sealed, for example, with electrical tape, and the microwave will not beep loudly (photo on the right).

Protective diode 2X062H close-up.

The 2X062H protection diode is mounted mounted on a high-voltage capacitor 1 µF x 2100 V (photo on the left).
The inscription on the high-voltage capacitor (photo on the right).

In order to find the reason for the operation of the protective diode 2X062H and, as a result, the fuse blowing out, the resistance of the magnetron filament circuit was checked; it turned out to be extremely small (about 0.1 Ohm); it was not possible to accurately measure it with a conventional multimeter. According to the reference data found for this magnetron, such a low resistance was normal for a working magnetron, or more precisely, it should be 0.07 Ohm. The resistance between the magnetron body and its terminals was also checked, the resistance turned out to be “infinite”, as it should be. From these measurements, it was concluded that the magnetron was conditionally serviceable (in the absence of the possibility of deeper testing). However, when dismantling the magnetron and removing the protective metal cover, traces of excessive local heating of the coils were revealed (the insulation enamel was darkened), but the wire itself was not damaged. To ensure the conditional serviceability of the high-voltage transformer, the direct current resistance of all its windings was checked. The resistances approximately coincided with the reference data. The measurement results were recorded with a fountain pen on the transformer itself to make it possible, if necessary, to double-check the measurements in the future.

Magnetron Panasonic 2M211 (photo on the left).
View of the furnace with the magnetron removed (photo on the right).

Magnetron. View of the emitter (photo on the left).
Magnetron. Side view (photo on the right).

Magnetron. The cover has been removed (photo on the left).
The slightly burnt insulation of the coil is visible (photo on the right).

As a result, it was decided to replace the fuse with a higher current one (10A), reassemble it and test the stove in operation. As it turned out, this decision was correct. After the last repair, the microwave worked perfectly, no extraneous noise or abnormal operation was observed. Of course, if the repair was carried out according to all the rules, then it was also necessary to replace the burnt-out protective diode with a new one, but its far from the lowest price, the absence of a radio store nearby and the urgent need for an oven in the kitchen outweighed the other arguments. At the end of the article you can see a few more photos of the repair process.

High voltage transformer. View of the nameplate (photo on the left).
The resistance of the high-voltage transformer windings was measured with a Mastech M-838 digital multimeter (photo on the right).

Contact on the body of one of the terminals of the transformer winding (during testing, you need to check the presence of this contact with a multimeter).

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

But as practice shows, most malfunctions have very simple causes, and a person who knows how to use a tool and has one can make simple repairs on their own. But for this you need to know. Let's figure out why this useful device may not work?

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

Before you begin your own repairs, you should learn about some safety measures when working with a microwave oven.

• Never, under any circumstances, should you start the magnetron of a microwave oven with the door open, or if the chamber or waveguide is damaged.
• Never and under no circumstances should you even try to connect a magnetron removed from its regular place. This is life-threatening!
• It is prohibited to start a microwave oven with a non-working fan. This may damage the magnetron.
• It is possible to carry out any manipulations with the furnace parts only after disconnecting from the network and forcibly discharging the high-voltage capacitor.
• All elements should be replaced only with similar ones.
• After completing all work, you need to remove all, even the smallest, objects from the waveguide.
• Running the microwave oven without load is prohibited. A non-metallic container with water must be placed in the chamber.

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

Why does the microwave oven not turn on and does not respond in any way to opening the door or to the controls?

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

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

In any case, you need to conduct a visual inspection of the inside of the microwave. To do this, you need to arm yourself with a flashlight and a magnifying glass and carefully examine all the elements.

The presence of dark spots, holes from breakdowns, swollen electrolytic capacitors, and drips always indicates abnormal processes. When inspecting, sniffing the parts helps a lot. The smell of burnt insulation, printed circuit boards or transformer oil is unmistakably detected and then the problem can be localized.

The backlight is on, the table rotates when starting, but the oven does not heat up.

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

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

The high-voltage magnetron circuit contains such important elements as a transformer, a high-voltage capacitor and diode, as well as safety diode, which burns out under abnormal conditions. It is very easy to find near the transformer, where it is placed in a special container. Its appearance will immediately show its condition. When replacing, you must purchase a safety diode only with equal ratings.

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

Magnetron has a connector that connects it to the transformer. Having disconnected the terminal, you need to ring the resistance between the terminals and the housing, and if they ring, this indicates a breakdown of the feed-through capacitors in the filter. The filter can be changed as an assembly, or the capacitor of the required value can be replaced separately.

By removing the magnetron from its regular place, you can assess the condition of the antenna cap, and if it is burnt out, it must be definitely replaced. You just need to change it to the exact same size - this is very important! At the same time, you can assess the condition of the magnetron insulator. A broken antenna or its housing clearly suggests replacement of the magnetron. If the microwave has a long service life, this may not be economically viable.

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

If you can slide a sheet of paper under it when the door is closed, then the door requires adjustment.

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

Control unit malfunctions

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

Most boards have their own fuse, which could have blown. The condition of the tracks, the presence of burnt and swollen capacitors, broken diodes and zener diodes - all this indicates problems. The power transformer can only be dialed by unsoldering it from the board.

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

Results

• A microwave oven is a complex and high-tech device that requires careful handling and unconditional compliance with all recommendations given by the manufacturer.
• Self-repair is only possible if the owner of the microwave has knowledge of electrical engineering and electronics.
• When making repairs, you should follow safety rules when working with high voltage and microwave radiation.
• Replacing the magnetron in a microwave oven that has served for more than 5 years is not economically viable.

Do-it-yourself microwave oven repair in video

Look how easily and cheaply you can repair this device without service, if the damage is minor.

repair of microwave ovens Panasonic and other brands

Microwave ovens or, as we call them at home, microwave ovens have become a part of our lives. They have rightfully earned the status of the main assistant in heating and even cooking food. They won our hearts with their speed, ease of use, compactness and durability. The microwave saves a lot of time, it is convenient to use and does not cause any harm to the body. It can be placed in any corner in the kitchen, hallway and office. Its only drawback is that it is very difficult without it. And this is rare, but it happens. Nothing lasts forever, and even microwaves break. The whole life is instantly disrupted. Panamaster will help you bring your favorite kitchen appliance back to life.

Good microwave ovens break down about once every seven years. The two most important parts of a microwave are the magnetron, the device that emits the microwaves, and the inverter board, which does the cooking. These parts have their own resources and exhaust themselves over time. The magnetron loses power or stops working completely, and the board may burn out. There are also mechanical problems - breakdowns of parts of the microwave body, which also prevent the device from working properly.

Our service center will promptly come to the rescue and correct the situation that seemed hopeless. We have been repairing microwave ovens of any brands and manufacturers for more than ten years and have hundreds of grateful customers who once reconciled themselves to buying a new microwave, but turned to us - and their equipment continued to work. Our specialists are first-class professionals in their field. They treat each order with the same care as their own equipment and perform high-quality repairs.

“Panamaster” gives a guarantee for the work done and always meets the client halfway. We can pick up and deliver the microwave oven to the desired address, we do not exceed the promised time frame and we always inform you about the cost-effectiveness of the repair. It is important for our service center that the client is served at the highest level, and that his equipment works like new.

We carry out qualifiedpost-warranty repair of Panasonic inverter and transformer microwave ovens. We repair all lines of models NN-ST, NN-GT, NN-K, NN-S, TT-S and others. We install original spare parts, which are officially supplied by the Panasonic warehouse.

Warranty conditions for repairs and spare parts

The Panamaster company provides a 6-month warranty on repairs of microwave ovens and a 6-month warranty on installed original spare parts.

Additional services

If you have problems with time and it is not convenient for you to bring the equipment to us, our courier will be able to deliver it to the service center and back at a time convenient for you. Use the service "Delivery of equipment" or "Call the Master"

Typical mechanical and electronic failures

Microwave ovens (microwave) Panasonic:

Doesn't turn on

Not warm

Grill lamp does not work

Spontaneous shutdown after a few seconds

The control panel does not work

Microwave door glass needs replacing

Doesn't turn around company table

The smell of burnt wiring during operation

When you turn on the microwave, the machines turn off (knocks out the plugs)

Gives error "H97"

Gives error "H98"

The display blinks and turns off during operation

Doesn't turn on, indicator shows 88:88

Microwave doesn't heat well

Extraneous noise inside during operation

Something sparkles inside

Mechanical grinding noise when warming up

The oven continues to operate after the end of the operating program (does not turn off by timer)

The cost of repairing Panasonic microwave ovens

The cost of the technician's work is indicated, taking into account the cost of diagnostics.

The RemStolitsa service company provides professional, prompt and affordable repair services for Panasonic microwave ovens with a visit to your home or office in the shortest possible time. There is no need to waste your time and nerves transporting a rather bulky stove to the workshop if the workshop can come to you!

When carrying out any Panasonic microwave oven repair The most important condition for ensuring the quality and efficiency of troubleshooting is accurate diagnosis. It is this that allows not only to very accurately localize the fault, but also to determine as accurately as possible the cost of repairing a Panasonic microwave oven at home. And if a “major” repair of the microwave oven is required, then so is its timing.

Of course, in some cases, expensive repairs to a Panasonic microwave may not be advisable, since the cost can be comparable to purchasing a new stove. But, as a rule, the repair is still cost-effective, because the most common repair of Panasonic microwave ovens at home in Moscow is instantly diagnosed and also quickly completed, without depleting the family budget.

We have been successfully carrying out urgent repairs of Panasonic microwave ovens in Moscow for a long time. Therefore, we can confidently state that we are able to cope with any malfunction and eliminate it quickly and professionally, with a guarantee of the quality of the work performed.

It is also worth noting that Panasonic microwave ovens require not only repair, but also maintenance. The specificity of their operation is such that during operation the stove is actively exposed to fat, moisture and other components of the dishes being heated or prepared. Therefore, comprehensive professional cleaning of not only surfaces, but also internal components is no less important than high-quality repair of Panasonic microwave ovens at home or in the office.

An equally important condition for proper operation of Panasonic microwaves is the use of a so-called surge protector with a fuse. It costs very little, but effectively protects household appliances from power surges. This helps to prevent the high-voltage fuse from blowing out in the equipment itself - such repairs of a Panasonic microwave oven are much more expensive than a filter.

Repair of Panasonic microwave ovens - main faults

Why doesn't my Panasonic microwave work? There can be many reasons for this. In addition to the already mentioned voltage drops, its performance is negatively affected by the use of metal utensils and utensils with metal elements, causing dysfunction or breakage of waveguide plates or magnetrons.

As already mentioned, fat and liquids are also one of the worst enemies of microwave ovens. Therefore, in the absence of regular and high-quality cleaning, a very unpleasant repair of a Panasonic microwave oven is possible, associated with a breakdown of the electric drive of the plate or fan.

The main symptoms of malfunctions and their possible causes look like this:

• The Panasonic microwave does not heat food or heats it very weakly (the magnetron has failed, the voltage in the network is greatly reduced);
• The plate does not spin in the Panasonic oven, but the light is on and the clock is working (the electric drive of the plate has failed or the door open sensor does not work);
• The microwave turns off during operation (the magnetron overheats);
• The touch panel does not work (the paths conducting the current are faulty);
• The oven does not turn on at all (the high-voltage fuse has blown, the transformer or safety diode has shorted).

Whatever the reasons for Panasonic microwave oven repair, the specialists of our service center are ready to help as quickly as possible and repair Panasonic microwave ovens at your home.