Originally posted by acoulter THANK YOU FOR THE TIPS! Can you elucidate? What / where is the aperture follower?
It's circled in the picture below. The LX originally used copper windings for the resistors, which was fine as long as the camera saw a lot of use, but most cameras didn't, and especially now, film cameras just aren't being used the way they were meant to be used.
The ISO resistor adjusts the meter sensitivity, the aperture cam follower resistor is what lets the camera do open aperture metering by simulating stopping down the lens electronically. You will sometimes hear people referring to it as the aperture simulator.
Anyway, copper will oxidize, consequently the feeler that runs up and down the resistor doesn't make proper contact, causing the problem you have seen.
Later LX cameras did use gold windings. I had all three of my LX bodies sent for repair while Pentax Canada was still servicing them. I had the ISO and aperture cam follower resistors replaced with the new style ones at that time.
If you shoot a roll of film a week, the aperture cam follower resistor should stay clean, but do exercise the ISO resistor frequently by rotating the ISO adjustment dial from stop to stop multiple times whenever you load a new roll of film, or weekly if you tend to shoot sporadically with the camera.