My 30 year old Minolta's meter quit mid roll and I fixed it with a pencil eraser
Pulled a roll out of my X-700 about a month ago and the meter was dead, needle just sat there no matter what I did with the dial. Took the bottom plate off expecting a dead wire, but the battery contact had a green crust ring around it from an old cell that leaked at some point. Grabbed a pencil eraser from the junk drawer, scrubbed the contact for maybe 60 seconds until the metal was shiny, and the needle popped right back up. I used to spend hours chasing a fault like that with a multimeter, now I go straight for the contacts first. It still sticks a little in cold weather so I'll probably send it in eventually, but 20 shots later it's reading fine. Did these old contacts get worse over time, or am I just finding more of them now that every camera I touch is 40 years old?