My first post to this site and my first medium format camera. I picked this up dirt cheap at a Thrift store. All functions well and is in relatively good shape. However the shutter won't fire. It cocks and clicks but the blades don't move. Aperture seems to move smoothly. Are there any good tutorials online on how to disassemble and repair this? Are there known issues with this lens? Is it a common failure? I have repaired my own 35mm equipment before so I have some experience and mechanical knowledge. I really want to get this up and working. Thanks!