This problem is commonly caused by a turntable motor that has worn out and needs replaced. The following link explains how to access and replace one:

http://www.fixya.com/support/r3555716-replacing_a_turntable_motor_on_a_microwa

For the model number you have listed, the part number is 46-841666-3.

You can purchase replacement parts at searspartsdirect.com.

The site also offers helpful exploded view diagrams to assist you in parts location/identification. The motor is listed at item 001-20 under the "Cabinet" heading. If you have any questions, please post back and let me know. I hope this helps you.

NOTE: You also consider the turn table coupling, which is item 004-22. The underside of the coupling has a keyed slot that fits on to the turn table motor shaft. If the coupling becomes cracked, or if the keyed slot "rounds out", it may be slipping on the motor shaft and not turning.

My r-930ak sharp carosol is arcing inside at the top.I took the proctector off inside & has a small hole in it.where can I buy another one & will this fix the problem