Recently I bought used Technics SL-B300 Frequency Generator Servo Automatic turntable in good condition without owners manual.
The problem is that tone arm travel ONLY to the position where it suppose to engage 45 record. The tone arm disengage correctly in the end of the record. When I switch speed to 33 to listen LP, tone arm travel to the same spot for 45 record. What need to be adjust or clean?
You might have a look at this site: www.vinylengine.com hopefully for positive help from a fellow sufferer.
I'm no lover of auto-on and auto return type turntables as many involve nasty metal pressings hanging off the bottom of the tone arm pedestal -- which is simply dumb, given the trouble the arm already has playing your vinyl.
For example, a non operating Dual turntable was cured simply by removing all the metal pressings in the plinth and hard wiring the motor switch (which was no longer being activated by the metal bits, thus the problem). After that it worked and probably sounded better than when it left the factory.
If your Technics is in this category I'd get ready to do some pruning. If by some blessing it uses a minimum of mechanical parts and detects the arm position by optical sensors look for loose parts or dust on the sensors (after all this turntable is pretty old by now).