Ok sorry this took me so long.
I loosened up the black spring on mine, and found out it stops the LP's from dropping.
In the picture, I made the black arrows to show the direction that the little side rudder is supposed to go.
It pushes the record up and over to drop it. When you loosen the screw, it just moves over, and doesnt lift or slide the record. So this part isnt your problem if your records are actually dropping. Took me some time to calibrate it to get the records to drop again.
So I have to say again I think the problem is the back end of your slider and the stop switch. Something there between those two is preventing your turntable from turning off. By the way, this "rudder" is what tells the slider that there isnt any records left on the spindle.
Remember when I told you about this?
(L)Single Spindle<---(M)Unloaded spindle<---(R)Loaded spindle
If you can picture/watch the spindle, you can see the rudder move way out after the last record drops (unloaded spindle). I might have to amend the visual. The slider positions might be simple as this: (L)Unloaded spindle<---(R)Loaded spindle
When the spindle is loaded, the rudder gets stopped by the records, which stops the slider from going all the way in. When the spindle is unloaded, it goes all the way in, which should be triggering the stop pole i showed you. Problem is, you cant see if its hitting the stop pole when the platter is on. You would have to take the platter off and turn the cycle cam with your hand to see how its hitting the stop pole with records on and off. Prepare to get greasy!