Mamiya 7II 80mm Lens: Testing the Flex Cable for Meter Problems
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
A Mamiya 7II w/80mm lens came into the shop with a complaint of the light meter not working properly. First thing I check is the lens as they often have broken flex cables (cable that carries aperture information from the shutter to the rear of the lens mount). I test these lenses by looking at the resistance change as I adjust the f stop. It will change from around 7.97K to 1.08K on a lens with stops from f/4-f/32. I then adjust focus from near to far watching the meter and a broken cable will show up by giving infinite resistance. In this case, all checked well so there is an issue somewhere else, likely in the body. The second photo shows a new flex cable. They typically break at the end.
