The microwave was not made in the U.S.A.
I had a top brand over the range microwave built for a U.S company in the Philippines, a loud buzz occurred, and it burned.
I have the same brand currently, built in Maylasia, the loud buzz is back. The combined age of these microwave units is under three years.
I bought a counter top USA built microwave in 1980. It still works very well.
cassandra
December 2012
When not using the microwave the motor for the fan sounds like it's on when the fan is off? Can you help me with this problem? I cleaned the filters and that didn't help! Thank you
Lynne Milnes
June 2011
This guy has an extensive trouble shooting guide for this problem. If you have an electrical test meter, you can find the bad part: