Mamiya C33 Seikosha-S 80mm shutter inop

[micwag2]

My first post to this site and my first medium format camera. I picked this up dirt cheap at a Thrift store. All functions well and is in relatively good shape. However the shutter won't fire. It cocks and clicks but the blades don't move. Aperture seems to move smoothly. Are there any good tutorials online on how to disassemble and repair this? Are there known issues with this lens? Is it a common failure? I have repaired my own 35mm equipment before so I have some experience and mechanical knowledge. I really want to get this up and working. Thanks!

 

[Rick A]

You should be able to find an inexpensive replacement lens on line. Try KEH or watch the auction sites, they are interchangable with different focal lengths, so take your pick.

 

[micwag2]

You should be able to find an inexpensive replacement lens on line. Try KEH or watch the auction sites, they are interchangable with different focal lengths, so take your pick.

Been checking out eBay but I'd like to fix it if possible.

 

[Jim Noel]

If you are not a watchmaker, or have never opened a shutter to repair it, stay away. These things are full of tiny springs, gears, and other very delicate parts. Even with a complete repair diagram they arenot for the inexperienced. Either send it to a repairman or start looking for a replacement.

 

[Jack Fisher]

Shutter

The above advice is good. It is easy for an inexperienced person to destroy the shutter. That said, some people remove the optical elements and flood the shutter mechanism with naphtha (lighter fluid) and get it working again. This is not recommended since proper lubricants get washed away. If the optics are good, it is time for a CLA (Clean, Lube, Adjust) by a qualified technician - or a replacement.

 

[David Brown]

I took one of these apart one time. Then carefully boxed up the parts to send to the qualified person to reassemble ...

 

[micwag2]

Thanks for all the replies. It's nice to see an active forum for film enthusiasts. As everyone has stated these are pretty complex inside. But i do fine precision mechanical and electrical stuff for a living. That's why I wanted information about the procedure first. It's not that i can't handle the job. I want documentation since this is the first time I will attempt this on this particular device. I agree without proper knowledge and experience this should not be attempted, however, there's a first time for everything.
Besides, if I open it and can fix it, then good. If not then no loss as I have to get another one anyway. As I see it I only can learn from the experience. KEH has one for $59. As well as eBay has a few I'm watching.

 

[LyleB]

Have you searched the internet for a service manual? I know some are available online. Would need to know the specific shutter involved.

 

[micwag2]

Have you searched the internet for a service manual? I know some are available online. Would need to know the specific shutter involved.

I did briefly search but came up empty. It's a Seikosha-S 80mm f2.8 Mamiya-Sekor.

 

[micwag2]

Success!!!!!!!!!! Wuhoo!!!!!!!!!!!!!!! The shutter blades needed some persuasion. Just stuck from age and lack of use i guess. I removed the lens and the chrome bezel on the front of the lens to reveal the mechanics of the lens. All was in order so I GENTLY pushed the shutter blades toward the open position while depressing the shutter release and "click!" she fired. Nice. Just kept working the shutter lever then and now seems to be working great! Yeah I know "Never touch the shutter blades!" However after looking at it I came to the conclusion these weren't moving without some help. They probably need cleaning but thats minor.

 

[Rick A]

Yippee!! Oh joyful day! That'll save ya a few bucks. If you are as mechanically adept as you state, maybe you should get started doing camera repairs, I hear there is a major need for them in these here parts.

 

[micwag2]

Yippee!! Oh joyful day! That'll save ya a few bucks. If you are as mechanically adept as you state, maybe you should get started doing camera repairs, I hear there is a major need for them in these here parts.

Not sure if I'm ready to do work for others yet but I'm never afraid to try. The shutter blades are still gummed from age. I need to find out what is safe for use on them.

 

[John Koehrer]

You have the biggest part done. Lighter fluid or Coleman lantern fuel & flush clean it. Although they're both Naptha I seem to have less residue with the lantern fuel.
Remove the optics, use a drop or two of solvent, work the shutter & repeat. Work the aperture too, it's going to have some solvent migrate into it and there will be some surface tension & residue to overcome if it's not worked.

 

[Anscojohn]

My first post to this site and my first medium format camera. I picked this up dirt cheap at a Thrift store. All functions well and is in relatively good shape. However the shutter won't fire. It cocks and clicks but the blades don't move. Aperture seems to move smoothly. Are there any good tutorials online on how to disassemble and repair this? Are there known issues with this lens? Is it a common failure? I have repaired my own 35mm equipment before so I have some experience and mechanical knowledge. I really want to get this up and working. Thanks!

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There were never any issues, of which I am aware, with the Sekosha. I think it is a basic Synchro-Compur derivitive.

Go Phillies!