Toyota AD860 Needle Case Error?

Hope someone can help me out. I have an older Toyota AD860. It was in the middle of switching needles then got a needle case error. I knew it was moving to #12 so I moved it, but still had issue. I found the sensor ring on the shaft was loose so I tightened it. Now I think it is not sure where it is at. I get it to reset, but when I push start, it does a thread cut and errors again. Any ideas?