Hi John,
The first thing I would check is the coupler (#37 on the
break down diagram).
Remove the glass tray and pull the coupler up. Check it for any cracks.
If the coupler is fine then the turntable motor has to be replaced.
It can be easy replaced after the bottom panel removed - just two screws and the wire plug.
- The part number for the coupler is
AP2016754
- The part number for the turntable motor is
AP2024962
Here are the break down diagrams for the GE microwave
Model JVM1860SD001
Gene.