The S6, Reconnection Switch is normally a non repairable item. So no pictures to guide you . It IS possible to take it apart, and fix it, (maybe) I know several folks who have done that, yes. Most folks start to foam at the mouth, go nuke and throw it away, when trying to reassemble it. EVERY part has to go back in right. I have done a few of the smaller switches, and it certainly taxed my patience to the max.
If you can turn the switch knob, and not hear/feel the "Klack", I am going to guess the switch shaft is simply turning in the switch body, and not turning the switch segments. The how and why? Can not tell you. I guess I would pull out S6. I would not mark the wires, I would use the wire diagram to reinstall it, or a replacement later. After getting it out, I would test the switch. There is a switch schedule in the diagrams. If it works, good. If not, I would, I guess, if I had countless hours of free time, take it apart. But would sure be looking for a new one.
One other idea is that the knob, is turning on the shaft. That happens when the switch is "locked up", and will not move. At some point, the knob strips out the shaft hole. and just turns on the shaft.