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Hexarlove
Tinkerer
Username: Hexarlove
Post Number: 1
Registered: 11-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, November 18, 2008 - 10:49 pm: | 
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Hi, I just got my nice-looking Konica Auto S3 (and X-20 Flash).
It looks wonderful, and I know it has quite good, fast lens so I can't wait to see the outcome of it.
Unfortunate, the light meter system of my S3 seems going wrong.
The light meter needle tends to stick to under-exposure [red] area when I try to take my first shot just after removing my lens cap off or just after training at dark target area. It looks like trapping or sticking to something... :-(
But this meter needle stuck can be got well by slight tapping on the camera body.... Yes, by just a gentle slap of my hand, the needle swing back to normal area.
Furthermore, the meter needle cannot go higher passing '(f)16' scale when I train the camera to bright point. I think, the meter needle should go higer to red area which indicates over-exposure, shouldn't it? But it just stop at 'f16'.
For that reason, I'm considering fixing it by myself if possible.
BTW, I never tried real film-shooting with this camera yet. So I don't know whether the indicating meter needle matchs exactly with real aperture... I hope it does, anyway.
So, please tell me if you have any clue for that matter - because I don't know which part of light meter has gone wrong - and appropriate method/solution for fixing it.
Thank you in advance. :-) |
Nickon51
Tinkerer
Username: Nickon51
Post Number: 41
Registered: 05-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 20, 2008 - 05:15 am: |
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Meters are notoriously difficult to repair, but there are a few things that you can check.
Have a look at the pointer itself and check that its not binding on anywhere in its swing. There may well be a 90 deg bend or two in the pointer for the trap needle mechanism.
If that looks all clear then have a look at the armature mounting pivots at the top and bottom. the armature can sometimes jump out of the pivots and still partially work. The armature should be in the end pivots but there should be plenty of end play.
Check the magnet gap that the armature turns in. A common problem is dirt or grit in that gap. Use a blower brush or a squirt of canned air to clear any debris.
Final check is that the armature itself is not binding in the gap. If thats misaligned, then you may as well toss it out. Its impossible to get that right without the special jigs used in manufacture.
Use care when moving the meter manually. Toothpicks are good, nothing metallic.
Cheers
Greg |
Hexarlove
Tinkerer
Username: Hexarlove
Post Number: 2
Registered: 11-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 20, 2008 - 10:56 pm: |
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Thanks, Greg. It's very useful advice.
Yesterday I ventured on a fixing it by myself after checking your post.
The disassembling itself, surprisingly, was quite easy with simple tools while I never dismantled these kinds of complex cameras.
Once I took off the top, then I could see the light meter. I exam the needle in every aspect but I couldn't find any specific improper bending which could causes binding to other parts and limiting its movement.
Then, I decided to go further, I took off viewfinder, front panel and de-soldered 5 different wires, so the lens and meter parts are completely off the body. Additional visual exams was executed. Yet I failed to finding any clue to solve the problem. Everything seems alright. But, the meter still have a tendency staying in under-exposure area before tapping and shaking the body. And the needle can not swing to over-exposure area. (I think normal meter needles should be able to hit over-exposure area which is marked color red on viewfinder.)
Maybe There may exist an electric problem. In fact, I don¡¯t have proper 'px675' mercury battery that is supposed for this camera. (It seems we all have same problem here.) All I have is LR-44 alkaline battery. (...and yes, I know it doesn't have right property for this camera.) The next best battery would be Zinc-Air cell (i.e. Weincell or hearing-aid battery) which has small voltage gap with traditional mercury coin cells. Well then, I gotta get a new Zinc-Air battery, first. I may be able to report changes later with that.
However, the needle itself is abnormal, indeed. Because, when I point the lens to light sources like lamps, or the sun they are bright enough to make it over-exposure indication. Still, I find the maximum moving range of the needle ends at '16', not at [red] over-exposure area. I got to thinks there are 2 mechanical possibilities. One is the part of needle which is seen in viewfinder are bent little bit lower so I can't see it at Over-E area at all. If so, I may bent the needle little bit upper so it can stay in Over-E area when it has to be there.
The other possibilities goes like this: the other end of needle which isn't seen in viewfinder are moving reversely having rotating pivot as center axis. And its movement limited by upper and lower pegs[what can I say these? They look like cylinders covered by white rubber like material]. I picked the needle of this side moved to touch the lower limiting peg (that is limiting top position of the needle in VF) and confirmed the needle in VF couldn't reach Over-E area. So maybe I may adjust this peg little bit to fix needle movement limitation.
BTW, I also worry that this manipulation affect real aperture value. How can I know that the needle value is same with real aperture value? If it is not, how can I make thsse one-to-one correspondence?
p.s. For now, I just reassemble all part back again till I get the point of fixing it.
CK. |
Nickon51
Tinkerer
Username: Nickon51
Post Number: 42
Registered: 05-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 21, 2008 - 03:26 am: |
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The upper and lower pegs are just the meter stops. I wonder if the rubber on them has become a bit sticky. That could prevent the pointer from moving initially.
I would be reluctant to start bending the stops or pointer unless there is some evidence that they have been previously badly adjusted.
Is there any adjustment of the position of the scale that you see in the viewfinder? I would adjust that first.
Thats about all the generic advice that I can give. I would need to actually see the camera to be of any further help.
Best of luck
Greg |
Chenard
Tinkerer
Username: Chenard
Post Number: 26
Registered: 11-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 21, 2008 - 12:11 pm: |
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My S3 did the same thing. Cleaning & adjusting the stops fixed it.
Paul |
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