Microwave does not heat...buzzing sound

My microwave does not heat and makes loud buzzing noise…

Tested diode…showed infinity…checked bad…replaced with locally purchased part…part number did not match parts breakdown for my model # but was told it would work by salesman…does part number matter?

Tested magnatron…showed less then 1 ohm (.4 & .5) per terminal and infinity to case?

Tested capacitor…showed 0 at each terminal and infinity to case…ordered part and replaced but did not resolve problem

Unsure of where to go from here…any assistance would be greatly appreciated!

Hello. The loud buzzing sound is a sure sign of a bad magnatron I would replace [part]AP4057047[/part] Thank you and good luck !