So I recently bought a sx-70 off ebay! I was so excited, get it through the post, put my first pack of film in and bam! Put the film in and the dark slide pops out, go to take a photo, the viewer goes black and nothing is spat out... The viewer remains blank for a while and sometimes, 'sometimes' it spits out an image. Rarely... Now I've tried three packs of film, the first photo somtimes comes out and develops but thats about it... One of my film packs was a 600 film (with filter), which I used in my 600 camera perfectly.. I just put a new pack in the camera and the first photo came out about 10 seconds after the viewer blacking out.. but thats about it Im really cheesed off, I'd love some help. thank you.