Until this past Sunday my sister has used the 1985 GE over the range microwave with never a problem. I happened to be there Sunday when she was using it. It was run for a couple minutes without any trouble. When set again and start was pressed all that happened was the timer began to count down. I'm thinking the magnetron finally went? Would there be a fuse anywhere to check? If it is the magnetron any thoughts on the chance of finding a replacement?