When I turn on the microwave, it sounds funny and smells like something is burning. Also, it does not heat anything. Is it repairable?
The problem can be a bad diode, a shorted high voltage transformer or a bad magnetron. You have to perform the troubleshooting to figure out which part exactly is bad.
You can find some useful information in some of our previous threads: http://forum.appliancepartspros.com/microwave-repair/26218-ge-advantium-microwave-scb1001kss.html and http://forum.appliancepartspros.com/microwave-repair/4463-dead-kenmore-elite-advantium-120-a.html
The model number you posted is incomplete. Verify and repost it.
Gene.