Spacemaker 1800 Turntable

I replaced mine, and it took 10 minutes.
If the turntable doesn't rotate, either the small ac motor has failed, or the coupling from the same motor has come loose. Here's how:
Unplug the main power to the oven. Remove the 5 or 6 screws underneath the oven to remove the access panel to see the small ac motor. There will be an electrical plug with two wires connected to the small motor---unplug it. Take out the 2 screws that hold the motor in place, and loosen the holding coupler (found underneath the glass turntable inside the oven) Inspect if anything seems to look broken. If everything is mechanically o.k., then the motor is bad. It's a fairly universal part number, a low voltage ac motor. Make sure that the voltage rating is the same when looking for a replacement. You could check on-line with a search-engine or Sears. I found mine in another oven that was being thrown away. It was FREE!

Good luck, hope this helps.

If the noise goes away when you turn the turntable off, it sounds like you have a turntable drive motor that is going bad. They are fairly easy to replace and not terribly expensive. You can access the motor by leaving the oven in place and UNPLUGGED. Remove the bottom panel. You will need to remove the turntable coupler (the plastic piece that spins the glass carousel) and remove a few screws in order for the motor to come out through the bottom of the oven. There should also be a quick connect plug that plugs into the motor. The motor runs about $35 and the turntable coupler (if you wish to replace it as well), runs about $8. The part numbers are 769741 and 769278, respectively at repairclinic.com. I hope this helps you.