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Konica Auto S3: Shutter and self timer repair

by M. Feuerbacher, 2005.

The Konica Auto S3 one of the most attractive 1970's rangefinders due to its compactness and its sharp and fast lens. In my exemplar, the shutter and the self timer were stuck. When turning the exposure-time ring the whizzing of the shutter gears was clearly audible and the shutter blades were very clean. Therefore I assumed that the problem must be located somewhere in the mechanics between the shutter release-button and the transfer to the lens barrel.

Please read the instructions completely before you start.

1) Remove the film-transport lever using a spanner tool. Remove the rewind crank (open the film back, lock the lower part of the rod and turn the crank counterclockwise).

2) Under the rewind crank you find a screw and under the advance lever a nut. These hold the top cap. Remove them and take the top cap off.

3) Unsolder the black flash cable at the inside off the hot shoe. If you want to remove the lens barrel it you can remove the viewfinder at this stage. Open the two black screws on the left and one on the right hand side of the finder unit. Then the finder comes off as a whole.

(In a couple of the following images the finder is still on the body since I realized much later in the process that I should take it off)

The image shows the bottom of the finder unit whith the rod connecting it to the lens barrel (a) and the vertical alignment screw accessible through the film chamber (b).

4) Remove the bottom plate: Remove the three screws and open the back door.

5) Bottom plate removed.

6) Remove the self-timer handle. Then carefully remove the leatherette with a long sharp knife starting from the lens-barrel side. You dont have to take it off completely.

Now you can detach the front plate holding the lens barrel from the rest of the body. Remove the screws marked by arrows. On the other side of the barrel there are two more screws that have to be removed .

7) Open the brass screw holding the potentiometer housing. Now the front plate can be removed. There are five cables still connecting the barrel and the body. It is not recommended to unsolder them, since their ends are not easy to reach and you can do all the following steps with the cables connected.

8) After the removal of the front plate you have access to the shutter and self-timer mechanism

9) The two parts marked by arrows are connected by the black spring but they should be able to move relative to each other.

10) In my Auto S3 they were stuch to each other due to heavy corrosion. I decided to remove them and give the assembly an oil bath. For this, the two shiny springs have to be removed (the black one can be taken off later, if necessary).

The spring in the front of fig. 9 loads the shutter release. Detach it on the lower side. The second one should be detached from the brass part at the top. In fig. 10, the spring has already been removed.

11) The corroded parts are now removed....

12) ... and can be subjected to an oil bath. Clean them carefully and repeatedly move the two parts.

13) Additionally I found that the light seal attached to the upper part of the lens barrel was degraded.

14) The old light seal is removed....

15) .... and replaced by a new one (2 mm x 2 mm x 50 mm).

16) Reassembly is straightforward. In my expemplar I additionally had to replace all light seals of the film chamber and align the distance meter.