Pioneer Turn Table PL-Z92 Speed Variable Problem

I seen to have picked this thread up in the middle so I don't know if this is relevant. Years back when I was doing audio service Pioneer had a problem with the material they used around the spring in the foot out-gassing sulphur. This attacked the speed control pots that were mounted internally near the feet. I don't know it your turntable was in the series with this problem but the fix was to replace the rubber spring covers and the pots.

If you have any pots near the feet cleaning them may give you a clue if they have been damaged.

Thank you for your comments. Not sure if they are relevant. When you write "around the spring in the foot out-gassing sulphur" I am puzzled. I have taken the lid off and notice a small round part, about 8 cm from the variable switch-speed, connected with it with four wires, soldered on to it. This must have something to do with the speed control. Does this make any sense to you? Klaas