This microwave has a strange fault sometimes works fine & sometimes after about 10-30 seconds just stops & clears display you can try again & it may work.
I think its a electrical spike/filter problem because it also clears the single oven clock with sits underneath the microwave.
No signs of burning on Hi voltage components insde !!
Because it is also affecting the clock on the (seperate) oven beneath it, I would remove the microwave and plug it into a different supply for starters. It sounds like a mains problem