microwave working EXCEPT for the heat!?

everything about our microwave is working, except for the heat. has this happened to anyone else? seems so odd. i would expect it either to not work at all or to fully work. i hear the fan, the plate rotates & the clock/timer works. any advice is most appreciated.

It sounds like the generator of the microwaves, the magnetron, is fried. How old is the unit?

There's a way to test it (disassembly required), but it's not for the faint of heart, or for someone not familiar with electrical stuff.

http://www.microtechfactoryservice.com/mag_test.html

This happened to us . Loose wire and bad door switches but it could be the magnetron. If it's old replace the unit . If not may be worth some exploration.

There is no "heat" in a microwave. If the food is not getting hot it means there are no microwaves being produced, even it there is a noise.

It's likely the magnetron. We just had the magnetron in our 5 and half year old above range microwave (Kenmore labeled brand but in fact an LG) replaced yesterday by a Sears technician. For $323 it was fixed by a very able technician who needed to spend several hours here (due to the difficulty of getting the oven back up and in line with the bracket again) and is now covered under an additional one year warranty. It would have cost me close to $300 for a decent installer to have removed the old one and replaced it with a new one we would have bought had it not been for my serendipitous call to Sears yesterday. One of the better deals I went with. It also could be as mod described. Or a diode, etc.