Quote Originally Posted by nwilkins View Post
non AI lenses may seem to go on fine but they do actually have to bend the AI clip out of the way in order to fit. I suppose it is possible that the clip could be bent, but really all the clip does is interact with the AI mount to move the metering ring. So if you are using an AI lens and the clip catches and moves as you adjust aperture then that shouldn't be the problem.
The ai clip seems to make contact and move when the f-stop is adjusted. So probably not it. Maybe it's just something that's broken like a bad contact or such. I found a repair manual on the internet but frankly -- I doubt it. The old fingers don't feel like they're up to messing with all those tiny parts.