Shutter stuck

[DabCan10]

I've got an M4-2 that the shutter has stuck open. I can move the film advance leaver about 30 degrees but that's it, the shutter won't fire, and the shutter curtains are stuck open. Also the film counter does not reset.

I read somewhere that this might be because I have something stuck in the film advance gears? Is this easy to get at to clean out?

thanks in advance!

 

[mooge]

stuck open? try messing with the shutter speed dial (was it on B?) and mashing the shutter release. I dunno. is the first curtain all the waay across?

If anything, something's stuck in the shutter gearing. fairly easy to get at if you've got the tools and knowledge...

good luck...

 

[nobbylon]

Are the curtains still attached? can you see any of the curtains? try the rewind lever on front of camera. You can also try slapping the camera base plate downward on the film advance side onto your palm a couple of times. I had one do this once and it un jammed and never did it again!

 

[mooge]

another thing to try: try turning the film advance sprockets to wind the shutter. I've done this a couple times when the wind lever was stuck.

if the camera was on B and is stuck open, the shutter button might not have gone up all the way... hitting it (like nobbylon suggested) or poking the shutter release might help.

 

[Vickko]

Wow, sounds brutal.

I'm guessing something is stopping the second curtain from either starting or completing its travel. The first curtain got released okay.

Maybe the felt light shield has fallen off the back of the film chamber and jammed into the shutter tape. Tends to happen in much older cameras, M2, M3's and the like.

But, all is speculation. I'd have to open it up (i.e. take top cover off, then body shell, to start investigating.

Doing anything with force won't help.

Vick

 

[DabCan10]

The camera was on 1000, the first shutter was almost all the way across, I gave it a little nudge and it fully opened, you can see the 2nd shutter inside the camera, I gave it a gentle nudge and it didn't move.

I think I'll have to find a tutorial on how to take it apart as I'm fairly certain something is just stuck inside, but I don't want to make it worse!

 

[mooge]

oh... well you won't be able to wind because the curtains haven't traveled far enough- they move past the film gate and the curtain drum will disable the wind lock. since the curtains were slowed, they won't have traveled far enough...

Vick might be right about that light shielding.


there's a guide here on disassembly.
would this be your first crack at camera repair...?

 

[menos]

Something strange, similar happened to me recently:

I attached a Motor-M to my M6 classic.
The camera was empty and I dry fired the camera a few times, as I never had the Motor on this camera before.

Then the shutter stuck (in my case not fully open, but one curtain half open).

I removed the Motor and felt all controls.
I could not advance the gears.

After I posted the situation on the forums, I got a response, to check the rewind lock lever!
I moved the rewind lock lever and the shutter immediately sprung into it's proper position.
The camera worked flawlessly thereafter as it had before - never a problem with it.

I don't know, what exactly happened.

Don't try any force!
Have a feel of all controls and check the rewind lock lever.

If you have any doubts, let a technician inspect the camera.

 

[uffda_x]

Hey Dave,

Let me know how the progress goes, I'm sure with everyone on this board we can figure it out. Just to get things cleared up....did you try the little rewind lever on the front? and you pulled the baseplate and removed the film? When you pull off the baseplate, that film counter should reset....if its not reseting when the film is removed, then there has to be a little piece of film or something jammed in the shutter gear....

 

[DabCan10]

Yep, tried the rewind lever, there was no film in the camera when this happened. pulled the base plate and counter didn't reset. Just not sure how to get at the shutter gear and don't want to wreck anything anymore than it already is....

 

[Vickko]

Ah, yeah. The rewind lever, when actuated, partially disengages the advance mechanism, so that the sprocket wheel can reverse, regardless of whatever "state of advancement" the camera is in.

As for the counter reset, removing the bottom plate pulls back a toothed plate, that normally holds/advances the counter wheel. Pulling back that toothed plate releases the wheel, and the wheel springs back to "-2" of zero.

That is a good clue, that the counter hasn't reset.

To get at all this, the top plate needs to be removed. Not hard to do, but you do need the correct tools to not make a mess of it.

Vick

 

[menos]

Ah, yeah. The rewind lever, when actuated, partially disengages the advance mechanism, so that the sprocket wheel can reverse, regardless of whatever "state of advancement" the camera is in.
…

Vickko, can you elaborate more detailed about this part:

"…Ah, yeah. The rewind lever, when actuated, partially disengages the advance mechanism, so that the sprocket wheel can reverse, regardless of whatever "state of advancement" the camera is in."

I am very interested in the technical details, as I have had repeated troubles with using a Motor-M and possible user fault in advancing the camera while the rewind lever has been engaged, leading to a half advanced/ locked camera.

What exactly happens?
How to unlock the camera (only possible by opening and realigning the gears manually, or as well from the external controls)?

I have now a M7 sitting with:

- shutter curtains visually properly advanced
- shutter release blocked (the release disk under the take up spool is in locked position, not aligned with the shutter release push rod)
- this leads me to the assumption, that either the advance has been interrupted or worse, that the shutter curtains have been fully cocked, but the film transport has been interrupted, leaving the release disk out of sync with the advance process.

I am preparing a trip to Solms, but I would like to fully understand the exact cause.