Hello.
I'm new to the forum and I need some help from you, experts.
Last week I was given an old Zeiss Ikon Contina.
The camera is very dirty and the lenses are blocked.  
It doesn't close.
I know nothing on the mechanism of cameras. (

I believe it needs film in it to work. Bypass the double exposure prevention by clicking the shutter release at the shutter (the lever by the o in Prontor). I see the shutter is already cocked (the lever on top of the shutter). Better explanations are fou

Thank you, Finnegan.
I'll try and give feedback later.

Not sure exactly what you mean by the lenses are blocked.  You squeeze the panels on each side of the lens to allow the front door to fold upward.
 
You can also bypass the double exposure prevention by twiddling the little gears under the frame open

Hello Connealy.
I mean that I can't close the lenses' compartment.
As I told above, I know nothing about the mechanism of cameras and this one is so dirty that I'm afraid to force and damage it.
When I have a little time extra, I'm go

The center disk in the advance knob is a retainer which unscrews in the normal direction.  It is then possible to unscrew the advance knob itself by turning it in the clockwise direction.  Taking off the two knobs on the bottom allows access to the advanc

Connealy, the knob is screwed. No problem there. Only this small part of the knob just fell out. It looks like it's broken...
I just need to take some time with this camera. Everything is blocked...
Thank you for your help.
Ana

Anat, that looks to me like the retaining screw has been sheared off, and what fell out is the head of the screw.  Other than that, I can't help as I've never had one of these to enjoy.  Maybe someday.
 
PF

Br1078lum,
as you say, it's only the head of the screw.
I think it's broken.
Do you think that it's worth to try to replace it?
Thank you
Ana

Gonna take some work, and a left-handed drill bit.  You've said you don't know anything about camera mechanisms, so you would have to take it to a reputable shop.  Lens cleaning and colimation, shutter cleaning and adjusting, a little bit of r

It will cost you more than the camera is worth...
That is what I thought

 
I don't think that it will get worst than it is right now so I think that I'll just let it be fo