There are two or more fuses on microwaves, but when they cut the power feed it is for something, if you bridge them you will find that your oven doesn't work properly, it will make weird noises and produce a power low in your home. If you want to check it, the main fuse use to be inside a plasitc tube with two wires on it's edges, one conected to a big condensator, and another one to the inner circuit.