GE Profile Microwave oven

Question

Everything works on the oven except it will not heat up anything. It worked fine yesterday and we didn't have any power surges or electrical storms. I cleaned everything ( vents, screens ) even though they weren't that dirty. I unplugged it for a half hour and restarted it. It sounds different and there is an odor coming from it now. It is a 2001 GE Profile Spacemaker JVM 1660 microwave oven