If you are sure that the magnetron is the cause of the noise and hum, you will almost certainly have to replace it. Signs of magnetron humming:
if you remove the clamp from it, the hum stops
the device on the magnetron terminals shows a short circuit
The only thing that can be checked is the presence of an award on the emitter cap. To do this, you need to remove the magnetron. If there is carbon deposits on the emitter, or a hole is burnt out altogether, this may be the reason for the inoperability of the magnetron. Sometimes it is possible to get out of the situation by replacing the emitter cap or cleaning it. But if there is such a defect, the magnetron usually does not work and the microwave does not heat. If the microwave is heating, then most likely this is not a defect in the magnetron.
If the magnetron just hums, but does not heat up, then this is a bad impregnation of the windings, which simply vibrate on the core and this has nothing to do with overload.
The magnetron cannot be repaired. If the above measures did not help, it needs to be changed, it is better for a specialist, it is dangerous on its own. If you need help with high end microwave repair, call us right now!