Stuck aperture ring on Mamiya-Sekor C 50mm f4.5

Hi everyone,

This lens was given to me by someone who thought it was broken.

The aperture ring is stuck on f4.5 and will not budge. All the other rings will move totally fine.

Anyone have any idea what's up?

Thanks so much,
Ryan.

No ideas but a suggestion. I have this lens. How long has this been happening? How long have you owned the lens? When was the last time you know of it behaving correctly?

Try actuating the shutter through all shutter speeds. Independently, move the floating element ring through its full travel. Notice any sticking or malfunction in the shutter or floating element ring.

Repeat the sequence again several times, and do this with the lens pointed down (at the floor) and the lens pointed up (at the sky). Something could be stuck and with a lot of exercise the aperture ring could get freed up.

Try the mirror lockup function if you have a cable release. Try the aperture preview lever. Try moving the M-X flash sync lever.