Cannot heat

Question

I was making popcorn when my microwave completely died - no power at all. I check the breakers, the breaker hadn't tripper. I reset the breaker and unplugged and plugged the microwave and all peripheral on my microwave - clock, fan, lights etc work fine. There is no heat - water doesn't boil when I turn the microwave on. It seems to make the regular noises - I cannot distinguish if it is just the turntable rotating or the magnetron kicking in with a "bong". Any suggestions. The microwave is about 4 years old but has minimal usage over the four years.