My Sharp Carousel Smart&Easy Convection (Model R-930AK-P, about 8 years old) was doing the same thing. Sometimes I heard the clicking noise and would open the door and jiggle the rotating plate to make it turn again. After a few months of doing this, it stopped rotating. Once it stopped rotating, it stops heating up the food as well.
I downloaded the service manual from manualowl.com/m/Sharp/R930AK/Manual/330660
But I don't see this exact problem described, so I looked up the Turntable problem and the Heating problem separately.
I read Procedure H (on page 21/52 of the PDF) on Motor Winding Test.
BUT, I don't even know how to find the Turntable Motor!
Would someone please give me a tip?
I've also read in another forum that "There are 3 door switches and if 1 of the door switches fails, it will stop heating and the turntable motor will stop. You need to figure out which door switch has failed and then replace the faulty door switch."
But right now I am thinking it is not the door switches since I had the previous "clicking and not turning" issues. What do you think?