I have a Kenmore Elite Microwave Model 721.7915. When opening the door to put an item in, the microwave automatically starts without closing the door or pressing any functions. I have tried unplugging and plugging it back in and it continues to do the same. Suggestions?

Yes, a bad door interlock switch would cause this; either the top switch or the bottom switch. (The middle switch is called the Monitor switch. If it were bad, you microwave would blow fuses as soon as you press Start.)

Probably has developed a short circuit in the door interlock wiring but the control board could be defective

I Agee with Ray - You can gain access to the lamp holder by removing the outter wrapper - unplug the power before you start

You probably have either a shorted high-voltage capacitor, or a shorted high-voltage transformer. And there is a 3rd possibility that should be checked first - the so-called "monitor switch" may be stuck in the closed position. There are usually 3 door switches in most microwave ovens, although some have 4. The monitor switch is usually the the one located in the middle of the door latch area.

If you need further help, reach me via phone at https://www.6ya.com/expert/ronald_e6b9572cebe3ad27

If this isn't close to what you have, search on youotube - there are lots of microwave door switch videos!

The door switch may be adjusted. If not then it will have to be replaced.

Is it actually heating or just making noise and acting like it's heating? (Put a cup of water inside and close the door.) IF it's actually heating, then you have a shorted relay on the main control board, and you will have to replace the board. IF it's just making noise like it's working, but it's not heating, then the problem is that one of the door switches is not working right (it's either stuck open or stuck closed).

If you need further help, reach me via phone at https://www.6ya.com/expert/ronald_e6b9572cebe3ad27

Check the door switches if one is bad it may think the door is being opened and stop the unit from running. If it is from a bad connection it will get worse as it gets hotter while running.

If the microwave oven operates with the door open it is a serious issue. DO NOT OPERATE IT. Call a technician immediately. The RF frequency is extremely dangerous. the safety switches inside the oven are malfunctioning and needs to be replaced