Looking at your picture and trying to remember I think that the sprung half cog might be in the wrong position for the spring tension to return the turntable. I suggest, if you dare, to open the one that works and take a look at that sprung half cog to see exactly where the half teeth are supposed to be, It may have moved on the shaft if a child continuously tried to manually force it to turn .
![[Image: Timber-Cogs.jpg]](https://i.postimg.cc/9DM1r0nc/Timber-Cogs.jpg)