Eleanor

My Juki LU 562 is not moving fabric through as it sews. I think it’s because the stitch length is set very short (I had a safety clutch trip, and whist fixing that, somehow this has happened). When I press the button to adjust the stitch length, the hand wheel is jammed and will not turn at all to change the stitch length, although it moves freely when that button is not pressed. Where should I start in trying to fix this?