New to the group.

I need help with repairing three 35mm slide projectors: 1) Kodak Ektagraphic Model 750H; and 2) Two Elmo Omnigraphic 300AF

All 3 have the same problem: the carousel tray will not advance, or reverse. When I push the advance or reverse buttons, I hear a buzz but there is no action.

If I had some instructions or a repair manual, could I possibly fix these myself? Any ideas what the problem is? Some kind of solenoid device gone bad, or needs lubrication?

Any help or suggestions would be very much appreciated!

Please feel free to tell me where to repost this if this is the wrong forum/thread. Thank you!