Will not heat.

Hi I've been out of the microwave repair business for a few years now, but the technology has remained virtually the same as far as I know. You obviously have some knowledge of them, as you know about the safety switches in the door. Microwave ovens are actually a very simple device, to test it, put a coffee cup of water inside, and set the unit on high for one minute. A second or two after you hit the start button, you should hear a fairly loud "bong" noise, and a hum that continues untill the time runs out. That noise is the magnetron starting up, and if that noise does not happen, then the magnetron or related circuitry is probably bad. NEVER open up the oven, as the magnetron may be charged, and must be discharged by a technician. If the sounds that I described are present, then the water should be boiling or close to it in one minute, if not,then something I've never seen has gone wrong. Assuming you had a year warranty on it, I know from experience that if you contact Goldstar customer service by phone, or letter, they will often extend their warranty a month or so to keep happy customers. Its worth a try. Hope this helps you out. P.S. Never operate a microwave without something inside (Non metalic)