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07-11-2016, 07:04 AM   #166
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The link seems to be broken...

07-12-2016, 09:59 AM   #167
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QuoteOriginally posted by reh321 Quote
I am now convinced, based on feedback from a user in another thread, that we have been discussing two different problems in this thread.

(1) Aperture control problem, the problem the Russians were dealing with, causes severely under-exposed images to be created, because the aperture is not adjusted; the easy "solution" for that is to use m42-mount lenses because their aperture control is totally manual and totally separate from the camera.

(2) Shutter operation, the problem niceshot was dealing with, causes totally black image to be created, because the shutter is stuck shut; I don't see any solution other than repairing {or buying a new camera} - and as niceshot has demonstrated, issues may cascade, in that case from stuck shutter to ruined motor.
You are almost correct, the problem is if the shutter is on its way out it can mimic the dark frame problem. So coincidentally I took anoth look at the shutter , turns out the thing must have been dropped at the factory breaking the side of it and a piece of plastic was stuck in the way of the second shutter causing it to jam
07-12-2016, 07:32 PM   #168
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QuoteOriginally posted by reh321 Quote
I am now convinced, based on feedback from a user in another thread, that we have been discussing two different problems in this thread.

(1) Aperture control problem, the problem the Russians were dealing with, causes severely under-exposed images to be created, because the aperture is not adjusted; the easy "solution" for that is to use m42-mount lenses because their aperture control is totally manual and totally separate from the camera.

(2) Shutter operation, the problem niceshot was dealing with, causes totally black image to be created, because the shutter is stuck shut; I don't see any solution other than repairing {or buying a new camera} - and as niceshot has demonstrated, issues may cascade, in that case from stuck shutter to ruined motor.
These two are easily confused also, as one of the downsides to the lens aperture not being controlled correctly is incorrect metering, leading to too fast a shutter speed being selected and a dark frame being produced.


Where the aperture control is failing though, you will likely experience a range of outcomes, right from heavily underexposed through to over exposed essentially full white images.


Shutter operation should be consistently all crap.


Yes, testing with a manual aperture ring equipped lens should highlight the core issue.

---------- Post added 07-13-16 at 02:36 PM ----------



This link isn't working, but I'm very interested in your findings and details around this 'spring slipped out' type issue and resolution.


Fingers crossed I'm dealing with the aperture only issue on my faulty k-30...


Thanks.
07-13-2016, 07:27 AM   #169
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QuoteOriginally posted by reh321 Quote
I am now convinced, based on feedback from a user in another thread, that we have been discussing two different problems in this thread.

(1) Aperture control problem, the problem the Russians were dealing with, causes severely under-exposed images to be created, because the aperture is not adjusted; the easy "solution" for that is to use m42-mount lenses because their aperture control is totally manual and totally separate from the camera.

(2) Shutter operation, the problem niceshot was dealing with, causes totally black image to be created, because the shutter is stuck shut; I don't see any solution other than repairing {or buying a new camera} - and as niceshot has demonstrated, issues may cascade, in that case from stuck shutter to ruined motor.
Could you let us a link to that other thread pls?

---------- Post added 07-13-16 at 07:56 AM ----------

QuoteOriginally posted by richandfleur Quote
These two are easily confused also, as one of the downsides to the lens aperture not being controlled correctly is incorrect metering, leading to too fast a shutter speed being selected and a dark frame being produced.


Where the aperture control is failing though, you will likely experience a range of outcomes, right from heavily underexposed through to over exposed essentially full white images.


Shutter operation should be consistently all crap.


Yes, testing with a manual aperture ring equipped lens should highlight the core issue.

---------- Post added 07-13-16 at 02:36 PM ----------





This link isn't working, but I'm very interested in your findings and details around this 'spring slipped out' type issue and resolution.


Fingers crossed I'm dealing with the aperture only issue on my faulty k-30...


Thanks.
In my case (I have a K-30 too) I am dealing with a failing aperture control. Why am I so sure?... Because I can clearly see the lens not being stopped when I shoot setting the aperture to any value other than its maximum. As a result the pictures are always under exposed unless conditions are of very bright light but never have I gotten an over exposed picture.
Using manual lenses (K mount type with aperture ring) has been a solution for me since I have been able to shoot 100% manual or use the green button to meter with the lens stopped down.
Also I have gotten a way to use automatic aperture lenses by placing an "artificial" stop on the aperture lever of the lens hence shooting at "fixed" aperture mode.
Hope we are both dealing with the aperture only issue and that it doesn´t lead to a shutter issue later.


07-13-2016, 10:32 AM   #170
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QuoteOriginally posted by JoseFF Quote
Could you let us a link to that other thread pls?
{following is the link that JoseFF asked for}
https://www.pentaxforums.com/forums/151-pentax-k-30-k-50/325602-shutter-dead.html#post3708755

Last edited by reh321; 07-13-2016 at 01:51 PM. Reason: link apparently not clear
07-13-2016, 12:51 PM   #171
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No, but just in case my aperture problems derive to a shutter issue...
07-13-2016, 01:08 PM   #172
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QuoteOriginally posted by JoseFF Quote
No, but just in case my aperture problems derive to a shutter issue...
Jose FF i did put the pictures up on aperture repair diy. But I am not confident in the rebuild so I am ordering up a donor body to compare them. When I do I will report back with a detailed analysis of it
07-13-2016, 02:57 PM   #173
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QuoteOriginally posted by reh321 Quote
A side-question: Did you discover that just one motor powers both the shutter and the mirror - so when that one motor fails, both the mirror and the shutter fail??
The mirror motor controls the mirror and the aperture, and two powerful electromagnet inside the shutter mechanism controls the shutter.

07-13-2016, 04:06 PM   #174
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QuoteOriginally posted by reh321 Quote
A side-question: Did you discover that just one motor powers both the shutter and the mirror - so when that one motor fails, both the mirror and the shutter fail??
It is my understanding that the two are separate. At exposure time, the shutter uses a linear motor built into the assembly. The mirror drive, OTOH, is visible in the various photos on this thread. It is unclear to me whether the shutter requires an outside motor to cock the mechanism with the Copal shutters used by Pentax. On manual wind film cameras, this was definitely the case. To make things even less clear, some shutters alternate directions between exposures.


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07-13-2016, 07:27 PM   #175
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QuoteOriginally posted by niceshot Quote
Jose FF i did put the pictures up on aperture repair diy. But I am not confident in the rebuild so I am ordering up a donor body to compare them. When I do I will report back with a detailed analysis of it
Thank you niceshot, looking forward to see it
07-17-2016, 01:26 PM   #176
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Is there a list of suitable donor bodies for aperture controller parts?

As I understand it, they've had the same design for many years (and one assumes it's in the new K-70 also), and I'd like to know what damaged/cheap bodies would be suitable donors for my new K-30?


Ideally there is a part that can be replaced by off the shelf components, but in the event that it's something requiring Pentax specific parts, it would be nice to know in advance which models would be suitable for this purpose.
07-17-2016, 01:33 PM   #177
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QuoteOriginally posted by richandfleur Quote
Is there a list of suitable donor bodies for aperture controller parts?

As I understand it, they've had the same design for many years (and one assumes it's in the new K-70 also), and I'd like to know what damaged/cheap bodies would be suitable donors for my new K-30?


Ideally there is a part that can be replaced by off the shelf components, but in the event that it's something requiring Pentax specific parts, it would be nice to know in advance which models would be suitable for this purpose.
Richard as far as Know you can get any camera from the Pentax DLl to the current series. As far as the shutter goes you would just swap the base plate. And on the aperture control block you just need to replace the motor or replace the whole thing. I is a major job. Just to rule out the mirror motor just apply 2 volts to it red lead is positive. It should raise the mirror , if it doesn't, you are in for a major job
07-17-2016, 03:01 PM   #178
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QuoteOriginally posted by niceshot Quote
on the aperture control block you just need to replace the motor or replace the whole thing.

Thanks. Is this aperture motor a standard part one can order separately from the likes of aliexpress etc?
07-17-2016, 03:05 PM   #179
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here is the link Pentax K 7 Digital SLR Replacement Mirror Motor Repair Part New Genuine | eBay
07-17-2016, 03:40 PM   #180
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Thanks


Still haven't had time to sit through the epic threads on this aperture problem root cause.

Is the motor linked to above a solution for this? Just that it refers to being a shutter motor, which in my case the shutter still works fine. Recall posts suggesting they are linked, but other make reference to electro magnetic solenoids sticking etc.
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