Bosch HMB5051

[Lydia22]

I picked up a Bosch HMB5051 for free from someone who was giving it away because it was broken. Figured I'd tinker around with it for fun. Never have worked with microwaves before, but have done some electrical stuff. It was a bit confusing opening it up at first because it has an inverter which I was not expecting.

The microwave doesn't turn on at all. The ceramic fuse is blown, but all three door switches work. I checked them twice both manually flipping their switches and then opening and closing the microwave door to check that the latch was working correctly. All three worked. I checked the magnetron using the multimeter across the the terminals and got continuity. There was no continuity from the terminals to the magnetron casing.

I don't want to replace the fuse only to have it blow again. Is there anything else I should be checking before replacing the fuse?

[GoodFerNuthin]

Very limited experience here from a DIY'er on a different make of microwave, but the high voltage capacitor and high voltage transformer can also blow the fuse.  Don't mess with the HVC unless you're sure it's discharged.

Here's the troubleshooting flow chart from my microwave.  You can start near the top at "Is Display Lit" and go from there.  It's GE not Bosch, but should be similar enough?