Microwave not heating
- Every thing, be it an electrical appliance or some kind of mechanism, has its expiry date and resource of work. In our world there is nothing eternal and the magnetron is no exception. The resource of operation of the magnetron directly depends on the mode of its operation. The more intensive the microwave oven, the less the magnetron will serve. In the course of long operation, the magnetron “ages and wears out”, resulting in such a malfunction as the loss of cathode emission, i.e. The cathode region is depleted with time, and it loses its ability to emit electrons into the working region, which causes the magnetron to stop working. The second malfunction that can occur during long operation is a break in the filament. In this case, you can give an example of an ordinary incandescent lamp, no matter how much it would not shine to you, sooner or later, it will still burn out. As a result of the breakage of the filament, approximately the same situation arises as in the first case. The cathode is not heated, hence – there is no emission. These two malfunctions are often encountered in practice, and if we theorize theoretically, we can assume that a third malfunction occurs as a result of a prolonged operation of the furnace – this is a failure of the magnetic system of the magnetron. In the event of a malfunctioning of the magnetic system, the electrons will simply fly from the cathode to the anode, they will not “circulate” along the anode surface and the microwave oscillations in the resonators will not arise. In practice, it was in magnetrons that I did not see this, but it was found in other devices containing permanent magnets. From time or under the influence of external factors, a permanent magnet can lose its properties (demagnetize).
Warning: A microwave oven can store a deadly amount of electricity (up to 5000 volts) in its high-voltage capacitor even after the microwave oven is disconnected from the mains. It is therefore extremely important to replace the electronic components in the microwave oven, only a licensed technical can lock them).
- Another very common malfunction of the magnetron is the breakdown of the pass-through capacitors of the magnetron filter. Check it out, the same simple, by the same tester. In the resistance measurement mode, you need to touch the probes of the device with one of the power terminals of the magnetron and its housing. If the device shows “infinity” – the capacitors are in good order (bottom picture). If the device shows any resistance, then one of the capacitors is broken or in a leak. If there are other serviceable capacitors, they can simply be replaced, if not, then it is better to replace the magnetron with a known good.
Fuse Appliance Repair will restore your microwave.
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