Mamiya RB67 repair & common faults
Excellent coverageThe Mamiya RB67 is a medium format SLR built for studio and location portrait work through the 1970s to the 1990s, across the original, Pro-S and Pro-SD bodies. It carries no shutter of its own: each lens has its own leaf shutter, and the body itself is almost entirely mechanical, so faults tend to sit in the leaf shutter, the interlocks, or the bellows focusing stage rather than in electronics.
Fully mechanical body, no battery needed to shoot · Leaf shutter in each lens, not a focal plane shutter · Revolving back with dark slide and back-seated interlocks · Bellows focusing on a rack · Optional CdS metering prism (battery powered, body itself unmetered)
Common Mamiya RB67 faults
Mamiya RB67 shutter won't fire
This is almost always the interlock system doing its job rather than a fault: the RB67 refuses to fire if the dark slide is still in, the back isn't fully seated, or the lens shutter hasn't been charged by the wind lever. Worth checking the dark slide is fully withdrawn and the back is seated home before assuming the shutter mechanism itself has failed.
Mamiya RB67 mirror stuck up
A mirror that stays up after firing points to the mirror return mechanism rather than the lens shutter, since the two are separate systems on this camera. It's a mechanical linkage or spring fault inside the body, not something a battery or switch fixes, and it usually needs the mirror box looked at rather than the lens.
Mamiya RB67 bellows light leaks
Because focusing is done by racking a bellows rather than moving elements in the lens, the bellows material itself is a wear part, and pinholes or split corners let light onto the film, usually seen as fogging or streaks concentrated at one edge of the frame. It's a consequence of age and use rather than misuse, and gets more likely the older the bellows unit is.
Mamiya RB67 back won't seat or lock
The revolving back locates and locks against the body through a mechanical interlock, and if that pin or catch is worn or misaligned the back can feel loose, fail to seat fully, or refuse to fire the shutter at all since the interlock reads it as unseated. Worth checking the back is pushed fully home and the lock lever is properly over before assuming the fault is deeper.
Mamiya RB67 meter not reading
The body itself has no meter, so a dead reading only applies if a CdS metering prism finder is fitted, and a no-response meter there is most often the finder's own battery rather than the camera. Worth swapping in a fresh cell before treating it as a fault, since these finders are a separate accessory with their own ageing electronics.
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Try it now ›Scatto is a reference tool for people who service film cameras. It explains mechanisms and quotes service data, but it cannot see your camera at the bench, so verify anything load-bearing before you act on it.