I have a GE Spacemaker over the range microwave (Model # JVM1440WD) that has stopped heating. It also emits a buzzing sound and a burning (electrical) smell whenever I try to heat something. Any idea of what could be going on?

I got this microwave used last year to replace another GE spacemaker that had stopped working. Wondering if it's worth the hassle to fix it or should I just get a new one (as long as it's compatible in the space). Thanks.