You might check to see if the gears are OK, if they are plastic they might be worn out. There are 2 gears underneath that work the feed dogs and the bobbin area. The knob is for raising and lowering the feed dogs. It also looks like your bobbin winder in is the winding position. Move it to the left for sewing and to the right for winding the bobbin.
Last edited by Pat M.; 12-06-2015 at 09:21 PM.