Whirlpool Electric wall microwave/oven combo

The other night I heard a popping sound in the kitchen coming from the wall microwave/oven combo, then it tripped the breaker. I flipped the breaker back on, and nothing heppened. I went back to the oven (whichis turned off), and opened the door, it felt really warm like it had been on, even though it wasn’t. I turned the dial from off to bake. When I did that it made a very loud popping sound and threw the breaker again. Before this we never had any problems with the oven.

The next morning, I was hoping if I turned the breaker back on I could maybe use the microwave. So I flipped the breaker on, and nothing worked. Not even the clock. The only thing that worked is the light in the oven. Any ideas what could be wrong? Thanks!

By the way, the model number is RM278BXV
The manufacture date is November 1992