Bosch Microwave HMV3053U/01 runs, but hums loudly after about 5 seconds

[palasr]

Model Number

HMV3053U/01

Brand

Bosch

Age

1-5 years

The unit runs and heats, it just hums quite loudly. I've replaced the diode and the capacitor with no change. This leaves me with either the magnetron, or the HV transformer. The problem is that they both check perfectly fine, at least on the bench with a multimeter. Resistance and continuity passes on both components with flying colors. I'm leaning toward the magnetron, but I really don't want to buy it, just to find out it was the HV transformer all along.

Your thoughts would be most welcome, or at least a set of educated guesses to help me narrow down the odds. Many thanks!

 

[Wx4usa]

I had two last week with the same symptoms. It was magnetron in both.

 

[palasr]

Thank you!

 

[Jake]

Here's the Magnetron for your model:
Magnetron 00648910

 

[palasr]

Welp, it wasn't the magnetron. First one arrived faulty (open filament), and replacement does the same exact thing as the old one. Starts, and begins humming loudly after about three seconds.

Since I've replaced all the other HV components, it looks like it must be the HV transformer. Alas.

 

[Jake]

This one should be for your model--->Transformer-High Voltage 00620524