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02-17-2017, 10:57 AM   #391
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QuoteOriginally posted by solatana Quote
But you see, solenoid is inductor, induces something.
There is also resistor.

You know what is meant with this?
My minor in college was physics.
I understand these terms.
Throwing words together as you have proves nothing, other than the fact that you know these words.
Please explain what the word "inductor" means to you, what is being induced and why you think it is relevant here.

QuoteOriginally posted by solatana Quote
Resistor can be very powerful, very strong resistance.
Will resist even if no resistance is needed.
These words mean nothing.
Please explain what the word "resistor" means to you, what is being resisted and why you think it is relevant here.

---------- Post added 02-17-17 at 01:27 PM ----------

QuoteOriginally posted by solatana Quote
'you' do not clearly understand.
Others understand it very "clearly".
When I said "we do not understand this", I was saying that
* different people have proposed different causes, including magnetization and friction/lubrication.
* sometimes observations differ depending on who is writing when

{Have you read, understood, and taken into account every post in this thread??

QuoteOriginally posted by JayDee on 1/11 Quote
FWIW, I didn't find my armature to be magnetized what so ever.
QuoteOriginally posted by solatana on 2/12 Quote
I think / guess: Magnetisation it is.


02-18-2017, 03:02 PM   #392
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QuoteOriginally posted by slartibartfast01 Quote
Has anyone in the UK with this problem had their camera repaired under the sale of goods act (or whatever it is called now)?This should protect against premature failure outside the warranty period.
I'm in the UK and my K-50 has gone back to the shop with aperture block after 2.5 years. The shop asked the Pentax rep. if some concession could be given but so far the answer is no despite another faulty Pentax coming in in the same week. The Consumer Rights Act is unlikely to help because the K-50 has clearly worked for 2+ years so when sold was not faulty.
I've yet to get the quote for a repair... I can see myself just using the aperture ring lens I have.
02-19-2017, 02:34 PM   #393
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More to the mistery

I performed the change of the solenoid in my ill K-30. I replaced it with one pulled from another Pentax camera.
Now my K-30 works like this:
  • In the continuous mode (Lo or Hi) and shooting continuously in the single mode at fast speeds (1/50 and up) it makes a series of pictures where always the first one is underexposed and the rest are satisfactory no mattering how long the series is.
  • In the single mode at speeds below 1/50 all shots are underexposed.
Does anyone of you guys have an explanation for this?
02-19-2017, 05:17 PM   #394
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QuoteOriginally posted by JoseFF Quote
I performed the change of the solenoid in my ill K-30. I replaced it with one pulled from another Pentax camera.
Now my K-30 works like this:
  • In the continuous mode (Lo or Hi) and shooting continuously in the single mode at fast speeds (1/50 and up) it makes a series of pictures where always the first one is underexposed and the rest are satisfactory no mattering how long the series is.
  • In the single mode at speeds below 1/50 all shots are underexposed.
Does anyone of you guys have an explanation for this?
What about continuous with slow shutter speeds and single shots with fast shutter speeds?

Inadequate power or sticktion could explain the first scenario but not the second.

It could be that the solenoid is only able to magnetize for up to 1/50 of a second before letting go and causing the aperture to close down. Try doing a longer exposure and seeing if it holds open for any amount of time.

02-19-2017, 07:40 PM   #395
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QuoteOriginally posted by JoseFF Quote
I performed the change of the solenoid in my ill K-30. I replaced it with one pulled from another Pentax camera.
Now my K-30 works like this:
  • In the continuous mode (Lo or Hi) and shooting continuously in the single mode at fast speeds (1/50 and up) it makes a series of pictures where always the first one is underexposed and the rest are satisfactory no mattering how long the series is.
  • In the single mode at speeds below 1/50 all shots are underexposed.
Does anyone of you guys have an explanation for this?
You broke the switch on the side door , the reason I know this IS i ACQUIRED a brand new camera because they couldn't figure that out.Fix that problem and I am good to go.

---------- Post added 02-19-17 at 09:44 PM ----------

QuoteOriginally posted by JoseFF Quote
I performed the change of the solenoid in my ill K-30. I replaced it with one pulled from another Pentax camera.
Now my K-30 works like this:
  • In the continuous mode (Lo or Hi) and shooting continuously in the single mode at fast speeds (1/50 and up) it makes a series of pictures where always the first one is underexposed and the rest are satisfactory no mattering how long the series is.
  • In the single mode at speeds below 1/50 all shots are underexposed.
Does anyone of you guys have an explanation for this?
one other though comes to mind, either your shutter block is on the blink or you mirror motor and or both. Good luck
02-20-2017, 10:20 AM   #396
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Finally I also did what had to be done...Situation started to become worse and I decided to sacrifice my K100D...So I changed the solenoid...but I removed the one which controls the opening of the flash...thus I had to remove just the top cover. Changed out with the green solenoid in my K500 and it solved everything...now it works like a charm. Plus I did a bit of horseshoe trimming for the green solenoid and put it back inside the K100 - also works like a charm - flash opens exceptionally well .
So after all it wasn't a sacrifice.
02-20-2017, 02:59 PM   #397
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QuoteOriginally posted by madphys Quote
Finally I also did what had to be done...Situation started to become worse and I decided to sacrifice my K100D...So I changed the solenoid...but I removed the one which controls the opening of the flash...thus I had to remove just the top cover. Changed out with the green solenoid in my K500 and it solved everything...now it works like a charm. Plus I did a bit of horseshoe trimming for the green solenoid and put it back inside the K100 - also works like a charm - flash opens exceptionally well .
So after all it wasn't a sacrifice.
Glad to hear! I hope more people aren't afraid to crack open their camera and tinker with them.
02-20-2017, 06:42 PM   #398
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QuoteOriginally posted by madphys Quote
Finally I also did what had to be done...Situation started to become worse and I decided to sacrifice my K100D...So I changed the solenoid...but I removed the one which controls the opening of the flash...thus I had to remove just the top cover. Changed out with the green solenoid in my K500 and it solved everything...now it works like a charm. Plus I did a bit of horseshoe trimming for the green solenoid and put it back inside the K100 - also works like a charm - flash opens exceptionally well .
So after all it wasn't a sacrifice.
Excellent news! And kudos to everyone who has dared to take their camera apart to attempt a fix or do some exploration to further the cause.

I believe the K-30/K-50/K-500 are otherwise very reliable and very capable cameras and worth the effort to try to fix.

Interesting factoid:
- Pentax used what I will call the "yellow japanese" solenoid in the K100s for both flash and aperture.
- They then later transitioned to the "green chinese" solenoid in the flash but the "yellow" for the aperture for the K-x/K-r and others.
- Then later again they transitioned to the "green" for aperture, removing the solenoid for the flash for K-500/K-30/K-50, etc.

Speculate yourself the reasoning behind this. Perhaps cost-cutting efforts, perhaps testing the waters with the "green" one first in the flash before committing to it for the aperture later.

02-21-2017, 12:12 AM - 1 Like   #399
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QuoteOriginally posted by caliscouser Quote
Speculate yourself
I don't want to think about it ... but I guess it could be a way to enforce planned obsolescence. Older pentaxes are quite durable and robust. Ok there is a huge difference in image quality, resolution, AF etc etc when you compare K100 to K500 but nowadays the improvements (considering final image) are marginal and many people can come to a conclusion that they don't need extra 8 Mpx in the K3 - basically for many there is no obvious reason to buy a new camera every couple of years - especially if they have initially decided to go with the entry level model (for Sunday shooters shutter life of any dslr is more than enough to last for years and years). So this might be an attempt to stimulate the buyer to choose a new body, especially if he has invested in lenses...Anyway...it is better than to put a time-bomb in the firmware.

Lately I have noticed that many things go out of order just basically right after the warranty has ran out - I have had 3 point-n-shoots over the years go nuts just after some 2 to 2.5 years of use (HP and Canon). And now entry level Pentax.... coincidence?
02-21-2017, 02:37 AM   #400
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For those who are repairing their cameras, are you discharging the flash capacitor before you start? If so, how?
02-21-2017, 03:16 AM   #401
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QuoteOriginally posted by ekip Quote
capacitor before you start
If you have the voltmeter, then you can check the voltage across terminals of the capacitor...It should have pretty considerable self-discharge rate so you can just take out the battery and wait.
If you want to be safe safe...you can use a small (0.25 W) resistor around 10 kOhms. I guess what is more dangerous is you having a static charge which might pop some ICs.
02-21-2017, 03:41 PM - 1 Like   #402
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QuoteOriginally posted by pepperberry farm Quote
QuoteOriginally posted by solatana Quote
QuoteOriginally posted by reh321 Quote
You will notice much disagreement about K-30/50 longevity.
There is zero disagreement about K30/50 longevity. Nobody disagrees.
There is nothing to agree or disagree.
I disagree - there are many, many, undocumented K-30/K-50's out there without any issues at all; like mine, with over 20,000 actuations and no problems at all...
if they are undocumented, how do you know they are out there? With exception of your K30 of course.
And how do you know they have no issues?

Crystall ball or pentaprism?

If you studied the aperture bock failure problem in this forum, you might have noticed: Many actuations and continuous use help that this
issue does not make an appearance.

You see, it will not help to disagree, because if your K30 has this green solenoid inside, IT HAS ISSUE, whether you like or not.
It is not the point to disagree, because if you open your K30 you will see this green solenoid WHICH IS ISSUE.

Of course you love to work with your camera. You use it very often. So this stupid solenoid mistake does not appear (so easely).

Point is that Ricoh used solenoid of cheaper manufacturer in China which is often misaligned.

Sometimes it might be well aligned .. by accident... and then your camera will not have accident....

This is why I used wordgame of resistor and inductor for our great-grandmaster of physics:
He can use sledgehammer and repeat and repeat same error thousand times and it will just make "alternative facts"
but no real facts out of zero by repeating zero.

He writes about "much disagreement" which is hilarious. Because "much" resorts to "himself", he is only one who disagrees really.
Out of principle. And now you know, even if you disagree, it cannot count, because there is nothing to disagree with.
Green solenoid is in your camera. Fact as fact can be (only other possibility would be that by same magic of crystal ball this
solenoid has changed colour, is no longer sick and now has beautiful color of transparent white)

When I ask him questions such "Bring evidence why there is reason to question about this (solenoid) being same failure/same part!" he just ignores.

Of course! Why? Because of zero evidence "on hand".

---------- Post added 02-21-17 at 03:54 PM ----------

QuoteOriginally posted by caliscouser Quote
Excellent news! And kudos to everyone who has dared to take their camera apart to attempt a fix or do some exploration to further the cause.

I believe the K-30/K-50/K-500 are otherwise very reliable and very capable cameras and worth the effort to try to fix.
I think like this as well, my K50 was very good, I liked to work with it better than with my K-S1. It has nice size and much better grip than K-S1.


QuoteOriginally posted by caliscouser Quote
Interesting factoid:
- Pentax used what I will call the "yellow japanese" solenoid in the K100s for both flash and aperture.
Did you use Takumar thorium yellow filter to look at this solenoid?

I slaughter today *ist body for 2 x solenoid. It is for sure not yellow but transparent plastic. Exactly same as in
photos shown here and in photos I have seen of Sony Walkman. Better to call it white?
02-21-2017, 04:02 PM   #403
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QuoteOriginally posted by ekip Quote
For those who are repairing their cameras, are you discharging the flash capacitor before you start? If so, how?
If you cannot find a resistor, use some 12V car-lightbulb (insulated of course).
02-21-2017, 06:21 PM - 1 Like   #404
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QuoteOriginally posted by solatana Quote
if they are undocumented, how do you know they are out there? With exception of your K30 of course.
And how do you know they have no issues?

you seemed to misunderstand my statement - no problem, carry on...
02-21-2017, 06:27 PM   #405
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QuoteOriginally posted by ekip Quote
What about continuous with slow shutter speeds and single shots with fast shutter speeds?

Inadequate power or sticktion could explain the first scenario but not the second.

It could be that the solenoid is only able to magnetize for up to 1/50 of a second before letting go and causing the aperture to close down. Try doing a longer exposure and seeing if it holds open for any amount of time.
I did several shooting series at lower speeds (1/8 sec) looking inside the lens to watch the opening and guess what...I could not see it stopping down any of the times, I clearly saw it closing completely but the pictures were the same: First one dark and the rest Ok. The data of the pictures indicated same aperture (5.6) and same speed (1/8 sec) for all of them. Now I understand even less... (I worked in manual mode)

---------- Post added 02-21-17 at 06:30 PM ----------

QuoteOriginally posted by niceshot Quote
You broke the switch on the side door , the reason I know this IS i ACQUIRED a brand new camera because they couldn't figure that out.Fix that problem and I am good to go.

---------- Post added 02-19-17 at 09:44 PM ----------


one other though comes to mind, either your shutter block is on the blink or you mirror motor and or both. Good luck
Hi Niceshot, How have you been? Are you referring to the SD Card door?
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