Noise and no Heat on Microwave oven.

First, I waste $65 by calling some "REPAIR" service. They showed at home and charge me that just to tell me
Second, I researched on the web and ordered a part, which was not the issue. I waste abnother $72
Third, I found Part-Select and got the right answer: the Diode was the problem. Ordered the part form Part-Select and it FIxed it !!!

Note: I did not buy a new microwave because this one is mounted on the wall and it will cost me +$800 just the lowest price.