If the focus and/or shutter-button is stiff, then old grease has dried out and hardened. You'll need to remove the top and clean/regrease the mech up there. Likewise with the focus. Be careful to mark the position of the focus threads to maintain correct focus calibration. It's been many years since I worked on these, so this general description is the best I can do. Good luck.
If the focus and/or shutter-button is stiff, then old grease has dried out and hardened. You'll need to remove the top and clean/regrease the mech up there. Likewise with the focus. Be careful to mark the position of the focus threads to maintain correct focus calibration. It's been many years since I worked on these, so this general description is the best I can do. Good luck.