Pro-Ject Debut Carbon Turntable working on and off

I didn't think there was a problem, necessarily, but it was suggested on this forum that replacing it might help since the original was getting old. So I went with that and got a new one.

For example, if the motor is running but platter is stationary, you might think there was a problem with the “belt”. Was that the case? If motor doesn’t run, then there’s no reason to suspect that the root cause of the platter not moving has to do with the belt. So what did you observe?

Yes, once I removed the belt, I could see the spindle that the belt sits on moving.

So - lift the platter, nothing's moving. Remove the belt, see the spindle moving. Put the belt back on, spindle, belt, and inner platter are all moving. Put the outer platter back on and it's playing.

I don't know if something is holding the inner platform from turning? I don't understand why removing the belt and then putting it back on makes it turn.

Either motor is dying (losing power) or like you say there’s friction somewhere that the motor only intermittently overcomes. But if records sound normal in terms of tempo, then I would either doubt friction hypothesis or look for an intermittent cause. Take the whole thing apart. Clean and relubricate the bearing. Check that platter spins freely. Make sure belt fits snugly around pulley and platter. Etc.

What Lew said. Next time, give the platter a shove to assist it starting up.