I bought this camera from a second hand dealer, who declared it faulty and gave me a generously discounted price. The film advance lever did not return to its normal position, and there was some resistance even when one tried to rotate it back. Although I was not familiar with this camera, I suspected a broken spring. This, indeed, turned out to be the case.
The removal of the top is not difficult. Unscrew the film rewind knob. (You need to open the camera's back and hold onto the fork in the film compartment to prevent it from turning.) Unscrew the narrow ring underneath. (On my camera this ring was already loose, so I could undo it with my fingers. If screwed on tightly, it might pose some difficulty, as it is hard to grab. Think carefully, before you attack it with pliers.) Next, take a spanner wrench with pointed tips and undo the pin-face screw in the centre of the film counter. The film counter disk, the lever, and a few other pieces (see picture below) can then be lifted off. There remains only one small screw to remove and the top will come off... with a little bit of prying and pulling. (The shoulder strap lugs won't cause a problem; one of them will come loose, and you can circumvent the other by pushing the top lid towards that side a little bit.)
The broken spring - which is of the coiled up metal ribbon type - is in the top right corner on the picture above. It should be attached to the cylindrical metal piece next to it, but it has snapped near that end. This is clearly visible on the next picture.
By the way, the viewfinder assembly comes off as one unit after only removing three screws. Don't loose the washers. Also, watch out for the coupling mechanism between the viewfinder and the lens. (See later.)
I was lucky that the spring broke near one end, because it was still long enough to be reused. Although, I did have to modify it a little bit. The next picture shows what it looks like after installation. I will also try to describe how the film advance / shutter cocking mechanism works...
On the top of the camera body there is a long metal bar (marked with no. 1 on the picture). It runs in a groove and on the underside of it there is a row of teeth. These mate with a cog which, after another linkage, rotates the shutter's cocking shaft. The metal bar is pulled along from left to right, when the film advance lever is rotated. The coil spring ensures that the film advance lever returns to its normal position when it is let go.
When checking the operation of the shutter cocking mechanism, it is important to remember that in the Ambi Silette the shutter release button gets locked immediately after each exposure. It is a good idea to observe and understand the sequence of events, and not try to mess around mindlessly with the various levers, shafts, and springs in order to make the camera do what it was not supposed to do. On the picture, I marked the shutter release button with no. 3 and the metal piece that locks it with no. 2. This piece is pushed aside, when the film is wound to the next frame. After the shutter is released, a small spring pulls it back, so that it locks the shutter release button again.
Here are a few words of advice: Check that the various bits and pieces move freely and effortlessly and lubricate them, if necessary. There doesn't
seem to be much room for error in this clockwork-like mechanism. If you dismantle the shutter cocking assembly you might find that either the
shutter won't cock, or it fires prematurely, when you put it back together again. The likely cause of this is that the cog and the metal bar
with the teeth are not lined up properly. There is only so much distance the metal bar can travel and on its journey it has to turn the cog
just enough to cock the shutter. So, the starting position of the cog in relation to the metal bar needs to be just right.
(Am I making sense here? I think this will become clear when you have the camera in front of you.)
* * *
While working on the camera a bad move resulted in an accident. I am too embarrassed to disclose exactly what it was, let it suffice that it involved the shutter blades. As the result of this, I had to take out and repair the shutter...
The front plate of the camera can be removed after unscrewing three longish bolts. These are accessed from inside the film compartment. They are found around the film gate, but may be hidden under a black sealant, which first needs to be scraped out.
The following picture shows the front removed. Let 's stop here for a moment to examine a couple of things. A great feature of the Ambi Silette is a moving viewfinder frameline that overcomes the parallax error. (You can see the frameline shifting in a diagonal direction as the lens is focused.) The picture below shows part of the coupling mechanism which is responsible for this (and for the rangefinder). A pin on the reverse side of the front plate and a C-shaped frame in the body are marked with blue arrows. The other noteworthy thing is the shutter winding mechanism. An orange arrow points at a shaft that sticks out from the shutter. A metal piece is fastened to the tip of this shaft to facilitate its rotation and this fits into the hollow metal piece to which the other orange arrow points.
If you were to take out the shutter from the front plate completely, you would have to pull off that metal piece I talked about earlier from the tip of the shutter cocking shaft, remove four larger screws and three smaller screws - all of which are visible on the picture. You would also have to deattach the flash sync chord. (On my camera one end of the wire was not soldered - I could just simply pull it out from a hole.)
This is basically all I wanted to say. Good luck.