DoghouseRiley wrote:I'm not sure if I understand all you've said.
But here's my two penn'oth.
I've a couple of Rock-Olas, but they only play 45s, (one plays small hole records, the other large hole ones) Neither has the facility for 33 1/3rd, nor do they have a working "intermix" mechanism. So I'm a bit in the dark. But I've noticed that the motor shaft is "stepped."
I thought the dropping of the three pins on those turntables with the facility, activated the mechanism which moved the jockey wheel from one position on the motor spindle, to the other.
If it will no longer play 45s and you've not done much to it other than lift the turntable on and off, it could be as simple as this. The grommets as have been mentioned can be an issue. If the motor drops slightly because of failing grommets, it won't now turn on the jockey wheel in the 45rpm part of the motor spindle and is permanently rubbing on the 33 1/3rd section at the top.
Incidentally with hardened or failed grommets you may get a background noise caused by the motor vibrations during play.
The grommets on the motor mounts are definitely corroded, thankfully that's a pretty easy solution for me. I have a number of rubberized pieces I can cut to fit to restore that aspect of the assembly, but I'm not sure that's a part of my problem (yet!). I can easily actuate the 45 RPM and 33-1/3rd RPM operation with what everyone is calling the "Sensor Lever Spring". I wouldn't be surprised if replacing the grommets would help out with some over the LF rumble the turntable exhibits, but the whole unit still sounds surprisingly decent, considering its age.