I have a beautiful looking Nikon F3 that appears to work well except for the ASA setting ring. Brand new batteriess, no corrosion in the battery compartment. Shutter speed and '+' and '-' appear fin in the viewfinder. I pulled up to unlock the spring-loaded ASA setting ring and it is very stiff to turn. I worked it back and forth a few times and that seemed to free it up but as I did that there were small "crumbs" of white substance coming out from the inside the ring mechanism. Now I can turn the ASA ring through its entire range (although not smoothly) but turning it has no effect on the meter readings in the viewfinder.
Turns out the white "crumbs" are broken bits of the glass ASA resistor ring. I found a couple of pages in a Google book review that cover this repair and I called Nikon to see if they stock the part. They do, part #40FB-FA1-684 ($29.60). I got a reasonable estimate for labor and decided to send it to John Hawley for repair.