Although there is nothing much to burn in microwave ovens, villagers often turn to me about their repair. Usually I change fuses, broken high-voltage diodes, sometimes I change burned-out magnetrons.
This trouble did not pass my grandparents either. The microwave burned in them, there was nothing on which grandmother’s delicious cakes were heated.
An autopsy showed that the reason is in the control board, namely in the microcontroller timer, which controls the microwave operation modes and at the same time shows the current time.
Well, the grandmother’s clock is good, no one will notice this loss, but the microcontrollers are tense everywhere, not just the grandmother. Climbing the Internet, I realized that the search, ordering and subsequent replacement of such a board does not make sense, so I decided to throw it out of the microwave at all. And a power regulator too. Anyway, my grandmother uses this microwave for fast heating of products only, and always at 100% power.
I found an old broken microwave in the barn, unscrewed the switch block from it and soldered the power wires to it. I cut a new front panel from a piece of white cladding plastic. Marker painted on it for grandmother dividing by minutes. Now everything is simple and reliable, like in a tank, and just one pen.
Despite my more than forty years of amateur radio experience and the specialty of an engineer - designer, I do not like all these microcontrollers, especially Chinese ones. I love reliability. The mechanics. Both in hours and in cars. And in the microwave too.