I took my AE-1 out of the bag after several years of storage. I press the shutter release and it fired only half way then stopped. I can not advance the camera or use the shutter release. There is no film in the camera. Also, if I press the rewind button on the bottom it will not reset after opening the back. I put in a new battery. I get a fast steady beep with the test button and the light meter works. Any help would be greatly appreciated.