My contax iiia did not release the shutter, only once out of 10 tries so i decided to take a look inside.
Here i am describing some steps on how to disassemble the contax iiia until you have access to the bottom of the shutter unit. Not a straightforward job at all. Some hints can be found on Henry Scherer's site (zeisscamera.com) and Rick Oleson's pages about readjusting shutter speeds on a contax iia - however the iiia with its meter complicates the things alot.
Also the "color dial" i.e. flash sync feature introduces lots of extra switches and springs...
(sorry no pictures but on the abovementioned sites you find some)
I took the camera completely apart, it was looking very scary. Here's how to:
I took off the wind and rewind buttons. Watch the little spring and ball inside the rewind button! it will shoot out like hell if you don't pay attention to it. Also, take notes about the orientation of the wheels on this side of the camera top - the film speed and the exposure calculator dial can be fitted back in multiple positions.
Then i took off the light meter cover. Four screws on the left and right sides. Try not to take the light meter apart, unless it's broken - it is very sensitive.
Then the light meter door. Two screws only, in the middle and on the left side("left" when the camera back is facing me). You HAVE TO take the light meter cover and door off.
Then the top camera cover. Four screws, two next to the wind and two at the rewind button - AND the little hollow screw on the back of the camera, above the flash sync socket, around the light meter adjustment screw. There should be a shim between the camera inside body and the top cover, at this adjustment screw! don't lose it.
Next, the light meter module had to come off. Nice that it came off in one. Two screws on the far left side, one screw above the shutter in the middle region of the camera top, and one screw next to the lightmeter "scale" (window") on the top. This last one cannot be completely taken out. Screw it until you can take the meter unit off.
Now you have access to the top side of the shutter unit. You can see on the left (=middle of camera) the slow speed simer unit, the two curtain-related shafts and the shutter release construction on the right.
If it's dirty over here, your slow speeds will probably won't work, or too slow. Mine was pristine clean and dry.
Next, the face of the camera (with the two windows) had to be taken off. (It is impossible to do this without taking the light meter module off...
)Four screws only.
This way you can clean the rangefinder windows in the inside, if there was fog or dust or whateva'.
Followed to take the shutter module off, since the top visible part of it did not show any problems so couldn't solve it from here. This is where friday late night (read: saturday dawn at 6) i had to stop.
The shutter module does not come out from the body if the lens mount is still inside. However, the lens mount cannot be taken out if the rangefinder module is not taken out simultaneously
So i did it, took out the RF and then the lens mount (which i needed to clean/relubricate anyway).
At this point entered the security guy (general check) and said to me, i will never be able to put those little things back in place. Heh!
However, i took out the shutter at this moment, YESS! together with the curtains and started to inspect it from the bottom.
Henry Scherer's webpage shows some pictures (i couldn't make any), however he does not go into details what is what and in what order to get the things off.
After about 30-40 minutes of cocking, firing, misfiring, i noticed that two little levers do not move out of the way as they should. Yes, it was simple. Two sliding platelets could not slide because the grease between them became grey from the fine friction-produced metal powder - grey and thick. So they moved hard and slow, not snappy as they should, and did not take the two mentioned levers out of the way, therefore the shutter release button went down with a faint click but no shutter release happened. Got it.
I took them off (the platelets; they look like quarter moons with a long cut hole in the middle where two screwheads are visible - these need to go off), cleaned in alcohol. Relubricated them a bit with very thin oil (we use it for vacuum equipment at 77K degrees or below, so i figured it should be okay to use it
). Screws back. (There's a very thin spring attached to the bottom of the lower moonshape-platelet AND the rest of the shutter, be careful with it. Also, remember the order in which the four shims, the two platelets and the screws have to go back.)
Well, everything started to run well from this point on.
Some complication with the rangefinder - had to realign when putting back, however, i noticed two little scratches on the wheels which aligned for infinity so it was no big deal after all.
I lost only one tiny little shim in the whole process - which i made out of thin copper foil to replace it.
Relubed the focus helical (is a bit stiffer now but i like it, it is not sloppy/noisy anymore) and remounted everything.
Wherever i've seen rub marks and dirty grease, i removed it and cleaned with small tissue soaked in 97% alcohol - leave time for it to dry! - and relubricated it but only slightly. No need for big fat greasy camera-inside.
Reassembly of all the parts/modules was happening exactly in the opposite order as the disassembly. Be gentle and hope for the best when sliding back the shutter module. SHould click in its place rather easily.
Still, i screwed up something - the B and T speeds do not work. (They also did not work in the beginning.) But i don't feel like taking it apart again for something i'll probably never use. All other shutter speeds seem great. However, it is quite a noisy shutter!!! not that "smooth" as i often read. Maybe i'm spoiled by leaf shutters like my tlr's and the yashica rf family.
I documented everything on some pieces of paper so i was able to fit everything back
otherwise it would have been a disastruous maze of little screws springs and shims. Used lots of tiny boxes to separate all the small screws and marked them correspondingly.
The camera inside was extremely clean - but dry also. It's far from the images of the corrosion shown on Henry's pages. Probably that helped to restore it. Also, i have access to a lots of small quality tools in the university labs; don't try this without the right tools!
PS: i take no responsability whatsoever if you make a mistake, like, put the shutter unit back in its place backwards or such. If you don't feel handy, don't do it!!! it's the most complicated camera i've ever opened. The yashica rangefinders and the tlr focusing mechanisms are nothing compared to a contax iiia color dial.