I've gone back and read all the posts...have you tried moving the A-J knob when the special knob is in the K position? On my machine, the special knob won't budge unless the A-J knob is set on something OTHER than A. It is possible that it got stuck somehow when the special knob was moved. Try setting it to K, and then push HARD on the A-J knob and see if it will move back to A.