I am not a service technician, just a guy who has worked on a lot of cameras and have noticed trends, and tried to correct the problems. I've experimented, substituted resistors, and come to conclusions about how far you can go to correct these meter problems. What happens to some cells through aging is that the lose linearity. Commonly it is called losing sensitivity, which is what it is. But I prefer the term linearity, because although through component substitution in the meter circuit, you may be able to pull the weak cell back in bright daylight, it will be incorrect at lower levels. The cell has lost linearity, and age is the only accounting for it I can tell. Some do and some don't. The FE was about a 1980 camera I believe, but I have seen cds cells from the 60's be just fine. Either CDS or silicon cells both go bad in about the same percentages. CDS is a simple resistor-only circuit, and Silicon phototransistors are amplifiers, but both go bad, or not. No reason.
Originally Posted by Ricardo Miranda