jammed shutter release in Leica M bodies

[menos]

I have experienced now the second body jamming it's shutter release in combination with the Motor-M.

This time, it is an M7 and it cannot be easily fixed from the outside it seams.
I have posted a thread here:

http://www.rangefinderforum.com/forums/showthread.php?p=1536520#post1536520

with the detailed description of what happened with the M7 yesterday in this post:

http://www.rangefinderforum.com/forums/showpost.php?p=1572327&postcount=4

Anybody familiar with this issue?
Anybody has any detailed description of the potential causes (the Leica M repair guide gives quite a detailed insight in possible causes)?
Anybody has factual info on known issues with the Motor-M (I find only vague descriptions like "the Motor-M is known for causing issues", but nothing definite apart from the low sync shutter speed frame drag or the bopping shutter release).

How can I check, if the advance cycle is actually completed, but the release disk is out of sync ?

Does it make sense, to remove the stud, which holds the release disk and actuate the shutter release and "reset" the cycle or is it likely to cause damage by a not properly aligned component ?

 

[Sonnar Brian]

I know very little about the newer Leica M bodies.

Sent a PM with contact information on someone to Email your question to.

 

[mooge]

how's the motor connection gear on the bottom of the camera look? it's directly connected to the drive gears so it should give some indication on the state of the drive...

actually, you can release the shutter after removing the plate with the loading diagram. the shutter release button pushes against a long flatspring which turns a latch to release the shutter drum, if you pull the end of the flatspring (you could pry it up with a screwdriver) AND the shutter is actually cocked, the curtains should go.

I can't see how the drive/shutter gears could go out of sync though...

good luck...

 

[menos]

Thank you Brian - I will contact him.

It is at this level not a question of being to tight, to get a repair done, but the need for knowledge, to understand these cameras and their different parts (and of course, the real cause of the issue ).

Thanks mooge - I can release the spring (it sits under a metal sheet cover, held by three screws).
It makes a small "click" and indeed releases the advance mechanism for about a 3 − 5º turn of the take up spool - this is so much, to release the rewind lever from it's rewind position.

Unfortunately, neither the shutter actuates (does it mean, it is not fully advanced ?), nor does the advance free up from it's jammed state (the advance lever still is blocked at approximately the starting angle, to wind the camera on).

Mooge - how can the motor connection gear look? Is there some indicator, I can look after? Apart from not knowing it's positioning during the cycle, it looks it perfect condition - no obvious damages.

I will dig further into the M2 repair manual, to understand the clockwork.

Any further helpful hint, to point me into the right direction is welcome.
At this moment, I figure, it would be the best way, to inspect the wind gearing under the top plate.
I have the correct tools, to get there, but I don't feel like it at this point (it's no battered M4-2 from eBay, but a very nice condition M7 0.85).
I don't fear damaging, but "Jesus Nuts" are not for me without proper knowledge ;-)

 

[mooge]

with regards to the motor connection gear- take a look at another camera if possible. if I recall correctly, that gear turns 180 degrees. maybe it should look like this at the end/start of a wind cycle.

do the curtains move at all when you lift the flatspring?

did you try winding the camera by turning the motor connecting gear?


okay, maybe we should take a step back...
at the end of the wind cycle, a few things happen:
-the 'click', the shutter drum is pushed to the cocked position, it's stopped by the release latch, and it disengages from the winding gears via a notch.
-the shutter lock washer plate thingy's slot (underneath the take-up spool) lines up with the shutter release button extension
-the lever advance mechanism is locked by the wind lock, a bar in the 11 o'clock position from the gear under the wind lever.

SO,
if the shutter lock plate was out of alignment, you should have been able to release the shutter via the flatspring. this is because normally, at the end of the wind cycle, the shutter drum is only held back by that one lever connected to the flatspring. that would lead me to guess that the winding gears and the shutter drum are still connected, meaning that the winding gearing is out of sync.

this is a semi-educated guess... I'm not an expert.

oh, and there's not that much to do with winding gears under the top plate; I suspect anything gone wrong would be on the bottom of the shutter crate. quite a bit of digging to get there...

one more guess: it was the motor that caused the problem, so the motor connection gears and their friends are very likely involved.

good luck,
Eugene.