Pentacon Praktica LB shutter speed problem

[ferditulum]

Hello everyone!
I just bought a praktica 35mm film camera. It is in really good physical condition. That was the reason for the purchase. The only problem is with the shutter speed. It works for two times correctly for all of the speeds and the third time it doesn't open or open like the fastest speed. Than two times works correctly again and the third time not. It is the same for all of the speeds. The light meter is working correctly too. With lens or without lens it is the same. I am giving a link to a video too. Where the problem might be? No problem for me to disassemble the camera. Please help me! Any advice will be helpful

 

[chuck3565]

That is a really weird problem. I've worked on these cameras for years and have never seen this problem. It probably is an issue in the shutter speed assembly under the top cover. My guess is that stiff lubricant is keeping a spring-driven pawl from moving on the third film advancement. I'd remove the assembly and soak it in solvent and lube it with some graphite. Good luck.

 

[ferditulum]

That is a really weird problem. I've worked on these cameras for years and have never seen this problem. It probably is an issue in the shutter speed assembly under the top cover. My guess is that stiff lubricant is keeping a spring-driven pawl from moving on the third film advancement. I'd remove the assembly and soak it in solvent and lube it with some graphite. Good luck.

Thank you so much! Should i remove only the top cover to access or i need the remove all shutter mechanism? Is there any manual?

 

[chuck3565]

You could lubricate the shutter delay mechanism without removing it. The issue is that the lubricant might seep where you don't want it to go. There are 2 or 3 flat head screws that attach the mechanism to the chassis. The mechanism surrounds the shutter speed shaft. The film counter mechanism has to be removed first. When the counter dial is replaced, one has to wind it up. I have an exploded diagram that I will upload. I also have the German language service manual that I can send to you if you will send me your email. It is 17 M. Chuck