I had a problem with a 301 where the handwheel would not move. I tried all kinds of things including removing the entire bobbin assembly. Nope, no thread. I finally sat it next to another 301 and compared. I found that the needle bar was pushed up in the non working 301. I opened the side and found a screw adjustment on the back of the bar. After I moved it down a little, the handwheel turned easily and the machine ran well. I don't know if this will help you but it's worth a try, I think. Good luck and just keep trying different things. You will learn a lot like so many of us that are still learning too! These machines are SO amazing- they really don't Break!