My Nikon FG arrived today but it seems to be "stuck"....like the mirrors locked up or something. I can't see though the viewfinder. I can't advance the film and when I press the shutter nothing happens. I replaced the battery (and tested it) so I don't think that's it. The lens comes seats and comes off properly. Thoughts? My gut feel is it isn't broken but something, most likely the mirror is "stuck" or locked up. Thanks!