OK, my monitor is like 29" and your pictures blew my eyes out, so I didn't look at them too closely. In any case, I have a PL-5 and here is what I would do:1. DeOxit the variable resistor and the white plunger switch on the speed control circuit. It may take a few doses.2. Also DeOxit the variable pitch resistors on the motor unit, you will need to remove the motor from the base to do this.3. While you have it apart, clean the dark hardened grease from the various linkages and renew with fresh grease. Less is better than more.4. Under the motor unit there is a cam assembly. Clean this carefully and use very light oil to re-lube it.If you can't hold speed after this, you may need a new speed circuit. I did for my PL-5. Cheap on the auction site and easy to replace.I know I am not beej, but I was "trained' by him on my PL-5 (as well as a PL-4 I purchased from him), so he will tell you himself that I am fairly well-versed in these fine tables.