if it's like mine, it has a bar sticking out in front that needs to be place over the screw that tightens your needle in place. that makes it go up and down and won't work properly without that in place.
i searched online but got nothing. do you not have a manual that has directions?
i take the bar and put my small finger under that while i place the foot in place to be screwed in. then i look and make sure the bar is in place and i'm ready to go.