fed nkvd, shuter problem

[tomaas]

when i release the shutter, all speeds looks ok except 40th speed... please see photo in link below, curtain remains open.
well, 60th speed sometimes, not much, also do the same.
tomaas

http://www.flickr.com/photos/24432469@N04/3202674597/

what ca i do?
thanks

 

[monocyte]

When tension on it is low, the closing curtain is more likely to jam at slower speeds; if this is a problem at 1/40 it likely will be at B/Z also. Check lubrication and that the curtain path is free of debris or obstructions, then consider giving the closing curtain a little more tension.

 

[tomaas]

at b/z speed works ok, always

 

[ZorkiKat]

Many things could be causing this.

A bit of film can be stuck somewhere in the shutter's path or the curtain itself.

Something may be out of mesh within the shutter's parts found in the top plate.

A very dirty and dried mechanism. Lost tensioning.

Or perhaps improper shutter installation after repair.

All of the above, plus some other reasons, will cause the defect you described. You will have to send your camera for professional repair if you aren't into tinkering. Or if you do this sort of thing, you can do the fix yourself.

Click on the FED Zorki link below for more details.