So I have been repairing appliances for about 5 years now on average 2-5 jobs a week, so I do not have a lot of volume to learn on. I find that I am getting more and more inverter driven microwaves, although I am not sure this has anything to do with it. I am presented with a Kitchenaid KHMS2056SSS that is not heating food. Inside I find that the magnetron is getting hot, so it is getting SOME power to it. Something tells me to open it all the way up and look at the waveguide. I had an Electrolux with similar symptoms that had burned a hole all the way through the top of the waveguide. So I look at the waveguide and there are three screws on the top of it. One of the screws is very loose and dark, another is somewhat loose, the third is tight and still shiny. I determine that the screws hold little silver "fingers", (baffles perhaps?) The baffle with the very loose screw was burnt and shriveled, the other one just burnt, the last one (closest to the magnetron) was like new and shiny. I have not idea what these items are, they dont show up on the parts diagram. I didnt feel good about not being able to replace these, so I returned the MW unrepaired to the customer.
Any idea what these are AND where you can buy them AND could this be the cause of not heating food?