konica S2 auto meter and wires

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cameratinkerer

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Hello.

The meter on Konica S2 Auto is not working. I have checked the CdS photo cell, it appears to be working because it changes its resistance with varying light. Battery check also works, the needle deflects to near the orange mark. However, the needle does not work in the camera when viewing a scene.

I have opened the bottom cover and the battery compartment. No corrosion.

But I see a contact with two black wires soldered with it. I am not sure to what this connects?

Can somebody confirm what that black contact is for? Perhaps the chassis?

Also, does somebody know the circuit diagram of the metering circuit of this camera?

Thanks.
 
Circuit as requested. The black wire tab is just a tie point. Its not uncommon for the switch contacts to become faulty. I think if you remove the screws the case can be pried apart and the contacts cleaned.
 

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cameratinkerer said:
Hello.

The meter on Konica S2 Auto is not working. I have checked the CdS photo cell, it appears to be working because it changes its resistance with varying light. Battery check also works, the needle deflects to near the orange mark. However, the needle does not work in the camera when viewing a scene.

I have opened the bottom cover and the battery compartment. No corrosion.

But I see a contact with two black wires soldered with it. I am not sure to what this connects?

Can somebody confirm what that black contact is for? Perhaps the chassis?

Also, does somebody know the circuit diagram of the metering circuit of this camera?

Thanks.
Click to expand...

I've worked on some of these that had broken connections
right at the photo cell. I gather it's a common fault with these
cameras.
 
I am trying to restore an Autoreflex T to working order and this forum has produced the most helpful info that I can find.The schematic up above is the kind of documentation that can be a big help when troubleshooting the low voltage ailments that seem to be common in this model of the Konica line.
I wonder how close that schematic is to the model that I am working on?
The battery compartment contact failed early on and I repaired that and also cleaned the test switch which didn't seem to help very much.I see some suspect solder joints which I intend to touch up today.The variable resistor and the fixed resistor in the schematic have different values than what I am measuring on my camera but I assume the basic circuit is the same.
I am getting battery voltage to the on/off switch but it sure would be nice to know what the circuit looks like while I am working on it.
I repair a large portion of my projects without a schematic so why should I need one now....lol.
Lazy,that's why!!
I have shot some pretty good pics with this camera so I know that it can do it but I need consistancy.
There are two pots in view,the one behind the prism does not seem to have any effect in the meter but the one on the left on the meter side of the frame does.I measured them before I made any adjustments but returned them to their original values.
I replaced the original cells with regular 675 cells until I found out that the 675 zinc air would give me just about the right voltage but I have gone back to the regular 675 while I am troubleshooting since my problem seems to be low voltage.My plan is to do the circuit modification with diodes when I get the low voltage problem sorted and stay with the regular 675 cells.
Any pointers that will lessen my troubleshooting will be appreciated.Ron G
 
cameratinkerer said:
Hello.

The meter on Konica S2 Auto is not working. I have checked the CdS photo cell, it appears to be working because it changes its resistance with varying light. Battery check also works, the needle deflects to near the orange mark. However, the needle does not work in the camera when viewing a scene.
Click to expand...

I think Bob has pretty much nailed it. Faulty connections right at the CDS cell are a common problem on these. Another thing to check is the state of the wires connecting to the battery compartment. The corrosive crud from a leaking battery can travel up the wire, corrode it, and cause a break well up inside the plastic insulation.
 
retro said:
I've worked on some of these that had broken connections
right at the photo cell. I gather it's a common fault with these
cameras.
Click to expand...

I checked the CdS photo cell but it was working properly. It varied its resistance as I changed light falling on it. No broken connections there.

I opened the battery holder assembly (two screws only). The trouble was the contact between the bottom metal strip and the metal part that connects to the wire (active during normal operation). It had corroded on the tiny area that makes the contact. Cleaning that corrosion made it work again.

Thanks
 
Now that I have my camera repaired I found a website with a schematic to it which I will post here for you.
http://silvergrain.org/Photo-Tech/Konica-AutoreflexT.html
What I ended up doing thanks to a very informative post on the KY Classic camera site was to calibrate the ASA settings with repect to the galvanometer which put me in the ballpark.I don't think that I would have ever figured it out on my own but once I knew what the basic setting was supposed to be I could make sense of it all.
I did not install the diodes to compensate for the increase in voltage that was expected when using the newer 675 cells and I tried the zinc air 675s and was not happy with the way they fit the battery compartment nor was I looking forward to the shorter life that went with them.It is so easy to adjust the circuit to compensate for the change in voltage that I chose to do that instead.
There is a variable resistor directly downstream and in series with the power switch which I set to drop .3 volts more than what it originally measured (2.8 volts down to 2.5 volts) which should take care of my camera circuits and the battery check circuit has its own adjustment,another variable resistor on the galvanometer side of the camera with the two yellow wires coming off of it and you can pretty much set it anywhere that you want,in my case I set it below the red line where I imagine it was from the factory but the setting is not important as it is only a reference and I expect that whoever might end up with the camera will have no issues with a low battery as long as they check it once in a while.
I checked it against one of my three or so selenium light meters and it seems pretty close although I am not certain that any of my meters are spot on either.The story goes if you give a man a watch he can tell you the time but give him two watches and he is never sure:).
I loaded it with a roll of Kodak Gold 200 and we shall see what we shall see.Ron G
 
My Konica T2 works excellent.The meter agrees with two of my three light meters,an old Tower and an old Sekonic.The other one,a Sekonic L-398 looks brand new and maybe I don't know how to use it but it seems way off.Granted,these are all selenium meters but they agree with the newer technology in my Konica and the results validate it.Thanks for the help along the way.Ron G
 
Interesting information here. I checked my Konica Auto S2 and disassembled the meter. The circuit that I noted is given in the attached file, it is same as has been posted here earlier. In my camera though, the variable resistor r was set to 7.8 Kohms (I think its max value is around 12 Kohms) and the fixed resistor R1 is 9 Kohms.
 

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cameratinkerer said:
Hello.

The meter on Konica S2 Auto is not working. I have checked the CdS photo cell, it appears to be working because it changes its resistance with varying light. Battery check also works, the needle deflects to near the orange mark. However, the needle does not work in the camera when viewing a scene.

I have opened the bottom cover and the battery compartment. No corrosion.

But I see a contact with two black wires soldered with it. I am not sure to what this connects?

Can somebody confirm what that black contact is for? Perhaps the chassis?

Also, does somebody know the circuit diagram of the metering circuit of this camera?

Thanks.
Click to expand...
Black are for the grounds and the two tied in together is just a junction, no more. The old mercury batteries destroy the ground wires were you can not see. Ohm out and most likely no reading will become of them. I replace all black and red wires without testing on my Konica S2 and S16's Red is a ground as well
 
I did not seen to clarify the red wire is a positive ground and will not be needed to replace. :bang: The two black wires at the junction runs from the meter to the CDS cell. It has the junction at the battery box for many reasons. One is to remove the wire needed and leave the other in place. I always replace the black wire from the battery box to the meter since the power from the battery travels the direction to the meter all the time. The wire for the CDS cell may be OK. If the wire breaks off the solder joint just by touching it, replace that wire as well. The fumes from the outlawed mercury batteries had traveled through the wiring under the insulation. That will cause a film fused to these wires where solder will not adhere to the wires no longer. Replacement wires are needed which should be new and 34 gauge in size. I had used 28 gauge wire before having no problems what so ever although the small hole in the shutters case had to be drilled out larger.
Another note sometimes the terminal is infected with the fumes of the old mercury battery. You will definitely know that if solder will not adhere to it and a donor camera will be needed for the replacement part. That is one reason I had so many of these models just for parts
I wish I could get information how to adjust the auto mode for I bought many of these cameras through my years and threw a few together from assorted different Konica S2's. All assembled with donor parts all work with the meter although the auto mode will not set the aperture and stays at f 1.8:bang:
 
Konica Auto S2 and S16

Konica Auto S2 and S16

A real pain to perform I may include for the beginner
 
Last edited:
cameratinkerer said:
Hello.

The meter on Konica S2 Auto is not working. I have checked the CdS photo cell, it appears to be working because it changes its resistance with varying light. Battery check also works, the needle deflects to near the orange mark. However, the needle does not work in the camera when viewing a scene.

I have opened the bottom cover and the battery compartment. No corrosion.

But I see a contact with two black wires soldered with it. I am not sure to what this connects?

Can somebody confirm what that black contact is for? Perhaps the chassis?

Also, does somebody know the circuit diagram of the metering circuit of this camera?

Thanks.
Click to expand...
Remove the battery box and remove the screws that hold the two piece box together. The blue wire is the one closest to the battery check button and you will see the terminal is shaped like a horse shoe upon removal. You must de-solder the wire to remove the terminal. Once out clean the terminal with vinegar and steel wool. Assemble and the meter should work as it has worked for me on numerous Konica's in this model
 
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