Pioneer PL -707 motor question

[Ty67]

The question I have for a pioneer PL 707 turntable motor is how does it work since there does not appear to be any moving parts. Thanks in advance.

 

[Beobloke]

Motor coils are etched onto the PCB under the rotor that you can see - electrical signals passed through these act on the thin black magnetic ring under the rotor that you can just see the edge of, and the rotor spins.

Just spin the rotor by hand to see it moving!

 

[beej]

Based on the pic that you posted your spindle assembly appears to be compromised. The spindle shaft cap is missing. That will result in the rotor being in direct contact with the circuit board. You should be able to rotate the spindle with your fingers. Given that pic I suspect you cannot.

 

[beej]

Below is an image of a disassembled motor board assembly for the PL-5. Different model turntable but similar design internally to your PL-707. Note the tip of the spindle. The tip on yours is missing. The spindle assembly is not a sealed system but it is a closed one. Yours, however, is compromised.

 

[Ty67]

Thanks everybody and thanks for the schematic. Apparently I was missing a single washer in which the thickness of it raised the rotor off the PC board the same amount so it could spin freely without any contact.

 

[beej]

Thanks everybody and thanks for the schematic. Apparently I was missing a single washer in which the thickness of it raised the rotor off the PC board the same amount so it could spin freely without any contact.

I do not believe that to be the problem but if installing that washer fixes it then so be it.