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08-30-2021, 10:39 AM   #16
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As for the K-S2 there is nothing needed except the most recent firmware update when using the latest PLM lenses.
The OP may or may not find this helpfull for his situation.

12-12-2021, 10:27 PM   #17
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QuoteOriginally posted by ydenk Quote
Can aperture cleaning resolve this problem? I would like to use a local repair shop and they have suggested cleaning is a common fix, but solenoid parts replacement might be problematic.
If they really recommended to clean the aperture, then this would be nonsense.
The aperture is inside the lens. I had once read a similar claim by one of the official repairshops in Germany.
They said that sticky apertureblades or sticky mechanism on old M lenses would cause ABF.

This of course cannot be:
The standard position of that part which moves the aperture-mechanism (at the K-bajonet left bottom) is downwards:
The springs are under tension, ready to release.
The same for the plunger of the solenoid, it is held by he magnetic force, the spring to bring it back into position is as well
in tension. Ready to release.
So actuation the solenoid actually is a release of tension.

If the solenoid does not actuate, ONLY because the plunger is stuck.

If you want to know more study:
Manual: Solenoid replacement: Pentax K-S2 (and K-70) - PentaxForums.com
plus:
A LITTLE BIT OF HISTORY: Development of the solenoid in Pentax cameras - PentaxForums.com

and if this was really the message that local repair shop gave you then better avoid it. But invite them to read those links.

Last edited by photogem; 04-04-2022 at 02:38 AM.
12-12-2021, 10:29 PM   #18
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QuoteOriginally posted by UncleVanya Quote
That would only make sense if the problem only happened with one lens.
How can a stuck solenoid produce ABF with just one lens?
And how would cleaning the aperture-block solve this impossibility?
12-13-2021, 06:11 AM - 1 Like   #19
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QuoteOriginally posted by photogem Quote
How can a stuck solenoid produce ABF with just one lens?
And how would cleaning the aperture-block solve this impossibility?
He asked about cleaning the aperture and I assume the shop meant the aperture of a lens. Sticky aperture can cause failures in aperture movements. My point was that if only a single lens is misbehaving it might not be ABF. But if many lenses are affected itís likely ABF. I was trying to suggest that diagnostically cleaning only made sense if this only happens with one lens. If so there are tests of the lens (flicking the aperture lever) that could be done to eliminate that possible issue from consideration.

02-17-2022, 12:07 PM   #20
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QuoteOriginally posted by UncleVanya Quote
He asked about cleaning the aperture and I assume the shop meant the aperture of a lens. Sticky aperture can cause failures in aperture movements. My point was that if only a single lens is misbehaving it might not be ABF. But if many lenses are affected it’s likely ABF. I was trying to suggest that diagnostically cleaning only made sense if this only happens with one lens. If so there are tests of the lens (flicking the aperture lever) that could be done to eliminate that possible issue from consideration.
I think the local shop has about zero idea about ABF when they suggest:

..... cleaning is a common fix, but solenoid parts replacement might be problematic.

The TO has enough lenses
so I think he must have studied the threads to know it is ABF.

With one single lens one can test ABF without any daubtdoubt:
How to detect aperture-block failure/stuck solenoid on Pentax K-70 - PentaxForums.com
Same procedure for any Pentax DSLR with a solenoid!

And very important:
A sticky aperture blade cannot lead to ABF!
As I explained in the last post.

Last edited by photogem; 04-04-2022 at 02:39 AM.
02-17-2022, 02:27 PM   #21
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QuoteOriginally posted by photogem Quote
I think the local shop has about zero idea about ABF when they suggest:

..... cleaning is a common fix, but solenoid parts replacement might be problematic.

The TO has enough lenses
so I think he must have studied the threads to know it is ABF.

With one single lens one can test ABF without any daubt:
How to detect aperture-block failure/stuck solenoid on Pentax K-70 - PentaxForums.com
Same procedure for any Pentax DSLR with a solenoid!
Clearly we disagree. I am trying to get to the bottom of this. If only one lens is affected it could be a lens defect. It doesnít seem likely but Iím asking questions trying to get data. If you prefer to assume the op has actually found out more than they posted and theyíre farther along in their diagnosis feel free. But personally I donít care much for assumptions if a direct question is a possibility.
02-17-2022, 02:40 PM   #22
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QuoteOriginally posted by UncleVanya Quote
Clearly we disagree. I am trying to get to the bottom of this. If only one lens is affected it could be a lens defect. It doesnít seem likely but Iím asking questions trying to get data. If you prefer to assume the op has actually found out more than they posted and theyíre farther along in their diagnosis feel free. But personally I donít care much for assumptions if a direct question is a possibility.
C'mon: If the OP has other lenses it will be obvious that he did the tests.
But as you know, there were no further data/answers.
It's not a lens which was affected, but a Pentax DSLR.

03-31-2022, 07:11 AM - 1 Like   #23
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QuoteOriginally posted by photogem Quote
With one single lens one can test ABF without any daubt:
How to detect aperture-block failure/stuck solenoid on Pentax K-70 - PentaxForums.com
Same procedure for any Pentax DSLR with a solenoid!
Did you mean to use the word ďdoubt??
04-01-2022, 06:20 AM   #24
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QuoteOriginally posted by reh321 Quote
Did you mean to use the word ďdoubt??
Indeed. I guess mistakes like this one are going to become more the older I get.
Sh... happens
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