I know you probably checked this already, but is the stop motion mechanism tightened?
If the clutch is disengaged (ie the machine is in bobbin winding mode) then the needle won't move up and down.
Edit: sorry, I see that quiltingvagabond and Joe already suggested this. I didn't notice that there were two pages in this thread!
Last edited by Jamesbeat; 06-13-2014 at 03:28 AM.