Well, maybe the Subject line got your attention. I just wanted to vent a little and warn others of this potential problem. My 2 year old Whirlpool microwave oven started producing a burning plastic type of smell. I didn't notice it at the time, but it was always when we did a bag of popcorn. The oven has a "popcorn" button on it, after all. Well, after a few weeks of sometimes smelling and sometimes not, the turntable stopped rotating. I removed the glass turntable and attempted to remove the plastic roller "spider" unit and it wouldn't come out. After doing some Google searches, others said it may not come up easily, so a little force in in order. I pried with a large screwdriver and it come out with not too much problem. However, hole in the bottom of the spider was definitely burned. So I proceeded to remove the motor. After more Googling, I found that Whirlpool put in a cover plate at the bottom of the oven which must be cut out with side cutters. Replacement was easy as you flip it 180 degrees, put the tabs in the slots and add a screw at the other end. Cute design! I removed the motor and its shaft end was also burned. The motor was rated at 30 volts AC, so I bench tested it with 30 volts AC and it rotated fine. I called my appliance parts guru and asked about the 2 parts, the motor and the spider. He said, "Ah making popcorn?" Together they were about $100. He said the bag transfers so much heat through the glass to the spider and shaft causing it to melt down and burn. Nice, Whirlpool, you put a popcorn button on a machine that will self destruct if you try to use it to make popcorn. I managed to moto-tool out the 1/2" diameter rotating plastic piece in the motor, making a 1/4" flatted shaft hole. I then fabricated a 1/4" flatted shaft from a piece of plastic and epoxied it in place. It was still able to grip the flatted hole in the spider. All is fixed and working now. When we do popcorn now, we put an old, I don't care if it breaks, plate under the bag. The middle of the plate becomes too hot to touch after just on bag. If this repair breaks, I'll probably get a 1/4" nylon screw and form the shaft from that. Or, I noticed on ebay, you can buy the exact oven for about $70 used .... basically, a boatload of parts for future fixes. BTW, my previous microwave oven, a built in GE, I think, never had this problem. It made 100s of bags of popcorn in its life and is probably still going strong in my previous house.
Also, Whirlpool WILL NOT SELL YOU THE PART due to "safety concerns". Thanks again Whirlpool for being a great company. I know there are many places on line where you can get the parts, albeit at a premium price. But I'm sure, if you had factory service replace the parts, they would cost the same or more.