Microwave fuse keeps blowing. I have a Sharp Carousel 1000watt microwave. I couldn't find the

Question

I have a Sharp Carousel 1000watt microwave. I couldn't find the model number. It lost power and I opened it up to check the fuse. I replaced the fese with a 250v / 20 Amp fuse. It powered on and I was able to set the clock. As soon as I tried to run it for a test, it blew the fuse. Any suggestions or "flow chart" advice would be helpful. Thank you.