- Hi Guys, My 500CM has decided to jam up. Tried nearly all the video tutorials online and can't find my particular fault. Fired and wound on perfectly normally 2 or 3 times then jammed. Shutter in lens is closed but I think not fired, auxiliary shutter is fully open and camera will not wind on, lens shutter will not fire. Only the back that was on it at the time will go on as the rectangular pin at bottom right of camera body is protruding and will not go back in. There was no film loaded as I was just keeping everything moving as I was advised to do when a camera was not used very much. Any advice would be greatly appreciated. Thanks, Dale.