To perform a repair microwave oven with his own hands, you need to know how it works. Before the repair of the microwave oven it is necessary to disassemble the microwave oven disconnected from the network. In electromechanical microwave ovens standard scheme.
Under the lid are transformer, fuses, doubler unit, consisting of a diode and a capacitor thick. This power supply circuit of the magnetron. Climb back with fingers or tools is dangerous. Inspect this area only after de-energizing.
By magnetron power depends on the speed of heating food. Microwaves that it emits, pass into the chamber through a waveguide. Acting on the water molecules in the products that produce heat. First warms the surface of food.
Waves do not penetrate to a depth of 3 cm. The product can be hot and cold outside inside. The inner layer is heated by natural heat conduction.
Power microwave oven was 700-1000 watts, magnetron heats. The internal fan motor and circulates cool air. Due to this the food is warmed evenly.
Dismantle the unit yourself
If microwave oven does not work, disassemble it to determine the cause:
- Before dismantling high voltage capacitor discharge, using a screwdriver of a dielectric material.
- Remove the cover: unplug the power cord, remove the side and the rear screws.
- Pull the back cover and gently lift.
When dismantling the front panel remove the control block unscrewing bolts grounding. Carefully, effortless application, disconnect the wires. Disconnect vyymite latch fastening and the screw that locks the assembly to the front panel.
troubleshooting
Before you disassemble the appliance, unplug it from the mains and wait a while. More often than not fail Details:
- circuit breakers,
- capacitor,
- diode,
- magnetron,
- transformer.
First check fuses. They are destroyed from the inside, and it is easy to see. If they do not look blown, then keep looking. Malfunction most parts can be detected using a multimeter.
Capacitor check, placing it in an ohmmeter mode. If you are connecting is no resistance, replace the part.
To test the high voltage diode, connect it to the network on the way to the lamp. If it burns poorly and intermittently, the fault is not present. If no glow is too bright, or the item is damaged. In this case, and damage to other components, replace the part. Beat in any case applies to it.
Transformer check carefully. For his discharge should take a few minutes and with a faulty resistor discharges any more.
When checking the condenser coils clean pliers terminals. Resistance of the primary winding in a rate of from 2 to 4.5 ohms. The secondary winding of the filament and the secondary high voltage and have a limit of 140-350 Ohm 3.5-8. If one of the windings could not ring out, the faulty transformer.
If the test found no damage, the problem may be in the magnetron. In this case, connect the tester in an ohmmeter mode to the power terminals. If the resistance 2-3 Ohm or device shows infinity, the item is broken.
These are the main issues that you can diagnose yourself.
Sometimes a malfunction due to the timer, the electronic control unit or other parts. In this case, the microwave entrust repair technician.
common faults
If the microwave fails, the failure is sometimes accompanied by characteristic signs.
If the microwave oven sparks, do not reheat food or make it long, then the heating element is damaged - the magnetron. Repair furnace with a breakdown, if it lasts more than 5 years, is economically unprofitable.
Microwave will not start. The reason may be a blown fuse, a problem with a door, thermal or damage the power cord. In the case of an open door repair the latch. If, due to changes in voltage fuse blows or thermostat can replace them with your own hands.
If the sensor does not work, but there is a time indication - it is in the tracks of conducting electricity. TouchPad will have to be replaced.
In the chamber there was an unpleasant smell and fumes. Inspect the interior surface of the furnace on the enamel damage. Remove the plate and inspect of radiotransparent dielectric. Part rubbing alcohol with stains or holes.
The oven operates, but off a few seconds. It is necessary to replace the thermal fuse.
If the microwave is buzzing, check magnetron for cracks and soot. Burned part have to be replaced.
Often the cap is destroyed magnetron. Aluminum housing cap in a few years breaks down under the influence of microwaves. Splashes of fat hit the protective mica gasket. If the droplets are impregnated fabric, there is a conduction bridge. Between the waveguide channel and a mica material appears arc.
Repair simple problems
If burnt cap magnetron:
- Strip cap descaled and expand to 180 °, since the load is only one part of it.
- Fashioned cap with his hands from the capacitor case.
- Replace the cap.
- The waveguide is exposed to contamination by oily substances. Spots fat cause sparking and burning may contribute to arcing. To prevent violations, close waveguide mica cloth.
- Fragment cut from the material and cover the waveguide output.
- Touch or conventional control panel may not respond to pressing. This is due to exposure to high temperatures after 3-5 years of continuous operation. The furnace is turned off or an error due to the control panel circuit contacts.
Instructions Repair Touch Panel:
- Disconnect the oven from the mains and disassemble the panel. It is a film with a pattern of buttons and membrane contacts the gasket.
- From left corner neatly inset sensor film with a sharp knife.
- After removing the membrane check the operation panel contact closure. Put in the oven glass of water. If it works - it is possible to repair the touchpad.
- Again, disconnect from the electrical contacts and treat alcohol. Stick to these places segments of adhesive tape or electrical tape. This saves on the contact closure and increasing the distance between them.
- Replace the top membrane back and check the oven operates. If does not work properly, turn off the microwave again, exfoliate membrane film and switching electrical tape. Repeat until all of the buttons will not function.
Due to sticking contacts microwave oven can operate without cut-off relay. In this case, the relay and start pinging vyymite ohmmeter. If the stove is working and quickly switched off, the problem is a thermal fuse. Such a failure is solved only in the replacement parts.
If the plate is rotated smoothly inside the microwave, the problem may be able of rollers or grooves due to the damaged engine. Clean the groove and if the results are unsatisfactory, replace the motor.
If rusted or burned furnace bottom, remove the housing, strip, cover the hole and cold welding. After solidification of the enamel paint for radiators and assemble. Allow to dry and only then operate the oven.
These failures are the most common and can be repaired by yourself. Observe safety during disassembly of the oven and when working with electricity. Do not try to solve the problem without such skills. Take the device to the service center, where they will be engaged in a professional.