The fuse where the microwave connects to the oven has burned out twice since we have had this microwave (less than 3 years).  It is very complicated to change out the fuse.  You have to pull the microwave completely out and then replace the fuse in the oven, then reconnect the microwave then slide the unit back in.  I appreciate that the problem is inexpensive but I think there is a flaw when a microwave fuse has burned out this often.