Problem with Mamiya 645 Super

[lxdesign]

Hey everyone,

A friend of mine gave me her camera to try and figure out a problem with it. Every time we load a roll of 120 film... the motorized winder winds the film forward and doesn't stop at the starting position like its supposed to. It stops around the 5 mark, then if you press the shutter again, it winds forward another 6 or 7 frames.... and then again to the end, until the entire roll has run through, and not a single shot has been taken.

Does anyone know whats wrong? Does it need to be repaired? Or what?

thanks,



David

 

[lxdesign]

correction to my message.... its a Mamiya 645 Pro, not super.

 

[chriscrawfordphoto]

Yeah it needs repaired. I don't know what's causing it. The body's gears are probably slipping, otherwise it wouldn't wind that far. The motor keeps winding till the body tells it to stop.

 

[Paul Sorensen]

You might want to see if it does this with only one particular back, or with any back. At least that way you could isolate the problem. It sounds like the gear problems could be in the back, which can be replaced at a fairly low cost.

 

[Greg_E]

The problem is almost definitely in the back. I have one of these backs that I converted to a pinhople camera, and stopping for each exposure is a function performed in the film back. Check to make sure the insert is working properly, and then replace the back.

 

[lxdesign]

gentlemen. thank you, but if this is the cause of the problem, then its both backs, as I have tried both, and it does the same thing for both. So perhaps its the gearing in the camera?

 

[Greg_E]

Did you use different inserts in each back?

Have you tried running film through the back with it off the camera? Load the film, twist the knob until it stops, should stop on the #1. To release the latch push the little pin near where the film is exposed and you can twist the knob again to #2, etc. I can't remember what happens if you hold the pin in and try to wind past the next frame, that could be a possible cause, but at least this way you can isolate between camera body and film back.