Works fine on oven and grill, cuts out out on microwave mode only. This can be on first use or on repeat. When it does cut out there appears to be what sounds like a relay clicking.
We have replaced Magnetron, PCB, capacitor and diode. Have metered door switches which are fine.
as far as I know this unit does not monitor the microwave circuit so even if you disconnected transformer primary it should still show the same problem
not sure if you have tech access but the only thing I could see that might help is attached