Rust and corrosion
I still cringe every time I remember a photographer using an F2AS in light rain without shielding it. Water and cameras just don’t go together, and I am sure this F2AS is not working properly now.

When buying an F2, always check for signs of rust and corrosion. If you can see any on the outside, then surely there would be more inside.

Here are some F2s that came for service with water damage. Horrible, but they were all restored after my extended service.
The shutter release collar was jammed solid with rust The mirror up lever was also jammed solid, and the DOF button would not spring back up
This one has some minor chrome spitting on the outside, but the inside had a lot of corrosion and some fungus Ditto
Ditto Ditto