[R.Giskard Reventlov]

Hello,

I just acquired a Pentax 6x7 and tried the camera without film to try the speeds of the camera. Unfortunately, I noticed the mirror always lock up when advancing the film. Even if I don't touch the MLU button.

It is not the common problem you see with mirror stuck halfway, because he always come back normally after I shot the picture.

So I tried something, I removed the lens and move up a piece of metal before advancing the film and magic! The mirror doesn't lock up, and the shot make the mirror flip up and down normally.

So now that I know my problem a little more of my problem, can anyone help me about that? I still don't know if the piece just need a little grease or if it's the mecaism of the button which is broken.


Of course, I really search the web and the forum to find a solution and I came up with nothing so please don't be hard on me if you find the solution somewhere

Thanks in advance and I really hope someone can bring me a solution!

[MysteryOnion]

Hey, congrats... and the first question just to get it out of the way is, fresh battery right?
Does the battery check light glows?
The shutter would look like MLU up when the battery is not installed or dead or connection is bad.


Continuing from the point about moving the "piece of metal" you pushed the mirror up by hand?
So you are able to cycle the camera... with film in it?
You should not be able to easily cycle camera without film in it... a procedure of turning the counter dial in required to dry fire.

More points depending on response.

[R.Giskard Reventlov]

Yes it's a fresh battery, light glows! And from what I read, mirror is stuck halfway when battery's dead, which is not my case.

I followed the procedure with the counter dial to be able to dry fire, I wanted to try the beast before using a film!

I didn't touch the mirror, don't want to ruin it.. it's really a piece of metal you can see on this two pictures: Pic 1 & Pic 2.
Look on the left inside the body, This is the piece of metal mentionned earlier. I just have to push it up gently and the MLU is deactivated, otherwise, it's always on..

Please tell me you can help me! ^^

[MysteryOnion]

OK, this is good... sort of...

The metal piece is the stop-down tab. The fact that you could coax is into operation does sounds more the issue of needing lubrication.

In this random image I have you can get the idea of the workings


Important is if both curtains are working with no signs of lagging.

The sequence of events put into actions are controlled by the gears as pictured along the bottom left of the image.

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Last edited by MysteryOnion; 06-05-2013 at 08:23 AM.

[R.Giskard Reventlov]

I got issue to see your picture in big size..

Is is complicated to unmount a Pentax 6x7, do you a tutorial to do it properly?

I dind't try to shot film, so I can't really see the result of the camera, but the curtains seems to work fine. Just sometimes the mirror flip down slowly, like it it was not that heavy!

[R.Giskard Reventlov]

Too young to edit my message -___- So I'm writing a new one.

I can see the picture now, it gives me a better idea of the whole thing.

Another question, if I unmount my Pentax, what happens with the light seals? Will they be broken or not?

[MysteryOnion]

I unmount my Pentax, what happens with the light seals? Will they be broken or not?

More than likely the foam is dried or sticky and in either case it is going to need replacing.... If you purchased it from a shop that had overhauled it and then it would be new enough not to need replacing.
However, since it has issues with the mirror return, then it was most likely not serviced. The opening I can outline... I'll try to draw it up and post it.

[R.Giskard Reventlov]

I just discovered something but I'm not sure on the meaning. I removed the battery and advance the film, in that case, the mirror didn't lock up, it flips normally and then stuck halfway.

Would it mean the issue is not mechanical but more of electronic?

Btw, I didn't remove yet the plactic cover to see how it is inside, don't have the right screwdriver, but as soon as I do it, I'll post pictures if I don't find the solution by myself.