[Not a Number]

you seemed to misunderstand my statement - no problem, carry on...

Thank gawd for the boriscleto™ option.

[pepperberry farm]

Thank gawd for the boriscleto™ option.

you know it - BTDT, got the t-shirt, etc...

these threads always seem to bring out the best posters...

(:

[reh321]

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.

You pop in and out with fancy words spinning tales worthy of the Brothers Grimm.
You use strange combinations of words and then reinterpret them if they lead you into trouble.
You speak of facts but dance out of the way when facts are actually mentioned.

fact: users have determined system is less likely to fail when using AA batteries, and more likely to fail when using fully charged D-Lion

fact: users have determined that filing away metal core from "solenoid" restores aperture system

fact from above: actions which reduce failure / restore aperture are those which reduce induction

Now, lets compare these facts to the end of your non-poetry which was more Theodore Geisel than Albert Einstein

So is in need of very powerful inductor maybe?

So you are a participant in the "much disagreement"; no explanation of the ultimate cause of this phenomenon, but lots of child-like words,and nothing that contributes to anyone's taking more pictures

[caliscouser]

Let's keep this thread focused on practical solutions, findings, observations and insights and dial back all the rest.

Lot's of contributions here from people all over the world, many non-native speakers.

Much learned so far I feel and more to come...

[solatana]

How many K100s, K200s, K10s etc developed this dark frame issue (they utilize identical mechanism)? Are there any data? I haven't heard anything. I personally have K100D and K100D Super - both still work just fine (~ 10 years).
Now - with K30/K50/K500 etc - there are quite a lot of dark-frame complaints. You don't have to be a Scherlock Holmes to figure this one out.

I think at sometime this source was some kind of reliable:

pentax k10d | Camera Shutter Life Database

It is like saying - everything is fine - let's ignore that 1 in 80 children has autism (which was something like 1 in 10 000 in 1965) because mine doesn't so I guess everything is fine - this is how it should be...

but now not anymore, very few K5II stated, but some K50:

pentax k 50 | Camera Shutter Life Database

but I don't trust, every nasty person can push competetion camera into red zone if want so.

I think this forum, german forum and french one are very reliable.

In german forum it was followed by call to members to send data, if K30 or K50 still works or is damaged.
Reaction was quick. One can even say here is rare case for statistics working alright:

Member who have K30 or K50 working want it to work in future as well. Is very simple psychological thing. Happens in so many fields of daily life every day. I defend what I like, I love what I like. Best example mother of new born baby. Nature bribes all mothers.
Makes them see own baby as most beautifull of world. Is defence for growth of species. Can be studied in animal kingdom.

I say this because for this members who have working K30 or K50 will reply quick for defending.
This shows result is quite reliable.

And my guess that in outside world of thousand K30 + K50 owners not member of any forum will not bother and just buy new one and throw old one away has strong possibility. This is how modern life often is. No bother or frustration.

---------- Post added 02-22-17 at 01:19 AM ----------

You pop in and out with fancy words spinning tales worthy of the Brothers Grimm.

Oh my dear
you flatter me

You use strange combinations of words and then reinterpret them if they lead you into trouble.

You mean like flatterfly?

You speak of facts but dance out of the way when facts are actually mentioned.

Because you mention Grimm brothers: Remember well one story where queen asks mirror some question?
You can try and ask mirror of your K30 who is most pretty one in world.

fact: users have determined system is less likely to fail when using AA batteries, and more likely to fail when using fully charged D-Lion*

Well, if I would use some lion in my body, yes Sir, my body will go on strike as well.
Good one, congratulation. you now learn playing with word as well.

But if use with fully charged Li-Ion, then argument is:

WRONG

Only is known that SOME users have not developed problem while (and not because) using AA batteries.
Usually users using AA batteries have reason for this. And this reason show that they use DSLR often!
This more possible reason why not develop problem.

Aparture failure OFTEN happens when long time camera is not in use!

Problem is not Li-Ion fully charged because in K-r, which follow K-x, problem was NOT solenoid but problem was powersupply was same one as of k-x which ONLY use AA.
If memory is correct: Li-Ion battery keep charge on high level for long time!

fact: users have determined that filing away metal core from "solenoid" restores aperture system

Correct sentence is:

Since few weeks some handfull users have tried with filing away thickness of plunger in solenoid. This leed to restoring aperature "FOR NOW"

fact from above: actions which reduce failure / restore aperture are those which reduce induction

you got something right, after all.

Now, lets compare these facts to the end of your non-poetry which was more Theodore Geisel than Albert Einstein.

As Heinrich Hertz and Ludwing Boltzmann had argument (following earlier proof by Leibnitz, Maupertius, Klein and Hankel in pure theory),
any equation that want have any empirical application (which is outcome with result) has to come to result other than zero (0).

So you are a participant in the "much disagreement"; no explanation of the ultimate cause of this phenomenon, but lots of child-like words,and nothing that contributes to anyone's taking more pictures

Your demand for ultimate cause of phenoment was delivered already by member athlonus!

But like child you close eyes, ears and what I call "thinking for oneself".

You have proof

- Take my word who is in the repair business for a long time and worked with Japanese teams designing cameras.

- The culprit is the new CHINESE MADE plunger solenoid. It is out of voltage specs and it MUST be replaced with a quality Japanese product such as Panasonic, Alps or Mitsumi made.

-Filing the part is quite laughable especially when you need to reopen your camera when it fails in a short while.

- Mirror box, Shutter and main board has NOTHING to do with that.

in front of eyes and not want to see.

[niceshot]

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 ----------


Hi Niceshot, How have you been? Are you referring to the SD Card door?

yes i am

[reh321]

Let's keep this thread focused on practical solutions, findings, observations and insights and dial back all the rest.

Lot's of contributions here from people all over the world, many non-native speakers.

Much learned so far I feel and more to come...

You are correct. I will try to resist efforts by self-appointed jesters to lure me into off-topic games.

[sys3175]

So, I'm reporting back, to bring this thread back to its topic. I repaired my K-50 some weeks ago using a donor part from a 15-year-old Samsung laptop CD drive (see here: K-30 / K-50 Aperture Block Failue - Repair Solution available - Page 21 - PentaxForums.com)

The result after about 900 shots: the camera works perfectly. So I consider the error fixed.

Regarding some other statements in this thread:

I've been using the camera on-and-off, partly only once in a month, then again, intensely. Usually, I've been using Eneloop batteries in the adapter cage. Around the beginning of this year (2017), I began using the D-Li109 battery more often. That's when I first saw the error. This was at around 5500 shots and at around 2 1/2 years after I bought the K-50. After powering up the camera, the first shot would be underexposed, the second would be ok. So, to test this, I switched to burst mode and the underexposed shots had the same Exif info as the correct ones. So I decided my camera had been struck by the problem we're talking about here.
To work around, I switched to Eneloops again and the error went away. But I was concerned that it would eventually show up again even with these Eneloop batteries. So I decided to change the solenoid.

So, I do not think that letting the camera sit on a shelf plays a major part in the development of this problem. But there's clearly a connection to the energy source.

The part I removed form the camera had a green insulator. The part I installed was clear, grey or white (can't remember exactly ;-)), but not green.

The moving part ('horseshoe') of one I removed form the camera was not magnetized at all. It moved smoothly and showed no signs of wear. The force needed to pull it away from the permanent magnet was surprisingly lower than with the part from the laptop.

I didn't investigate this thoroughly, but I think this part works as follows: the permanent magnet holds the moving part/horseshoe in place, while there's a spring connected to the lever inserted into the moving part. The solenoid can either annihilate the permanent magnet's field (counteracting), enabling the spring to pull down the lever, or it can enhance the field to pull the lever back to the resting position. It does this on every shutter release except when using the new eletrical aperture lenses.

So you have three parts in equilibrium: the permanent magnet, the solenoid, the spring. For some reasons, this equilibrium gets disturbed with the green solenoid so that it is no longer able to annihilate the permanent magnet's field. The lever stays in the upper position, because the spring cannot pull it down.

Conjecture: the lever staying up when it shouldn't might cause damage to the aperture block in the long run, which might explain the problems some people here have seen after using the camera a long time after the problem occured. So it might be good to address the problem right away.

Conjecture: the connection to the energy source might point to the solenoid getting out of spec.

Conclusion: While shaving off the horseshoe might put the parts into an equilibrium again, there's a risk that it won't, and also, that the part might degrade further. So, exchanging the solenoid seems to be the way to go, because this makes sure the permanent and electric magnets match each other.

Another conjecture: Putting the poor camera into burst mode and rapidly firing the shutter dozens of times might be doing more harm than good. I'm pretty sure that this means using the camera out of spec and might eventually kill the shutter/aperture motor and/or gears.
If you are stuck somewhere with a hung solenoid, it might be better to try loosening it using the DOF preview, that way, at least the shutter won't be unneccessarily activated.

Finally, regarding this thread: the K-50 is a mighty fine camera, it's light, has good ergonomics, good DR and low-light performance (ISO 3200 is perfectly usable and 6400 is also quite good when using Adobe Lightroom and adding some noise reduction.). As with everything, a complex system might break. Luckily, there's an easy, inexpensive fix.

So I'd like to suggest to some people here, instead of whining and insulting, move on and get over it. Either repair it, get it repaired, or get another camera. But don't make us subject to useless discussions.

'Nuff said ;-)

---------- Post added 02-23-17 at 06:15 AM ----------

For those who are repairing their cameras, are you discharging the flash capacitor before you start? If so, how?

I didn't, but I took care to stay away from it's contacts (which is not too difficult). But I didn't take off the top cover, if you do, it might be better to discharge it.

[reh321]

So, I'm reporting back, to bring this thread back to its topic. I repaired my K-50 some weeks ago using a donor part from a 15-year-old Samsung laptop CD drive (see here: K-30 / K-50 Aperture Block Failue - Repair Solution available - Page 21 - PentaxForums.com)

The result after about 900 shots: the camera works perfectly. So I consider the error fixed.

Regarding some other statements in this thread:

I've been using the camera on-and-off, partly only once in a month, then again, intensely. Usually, I've been using Eneloop batteries in the adapter cage. Around the beginning of this year (2017), I began using the D-Li109 battery more often. That's when I first saw the error. This was at around 5500 shots and at around 2 1/2 years after I bought the K-50. After powering up the camera, the first shot would be underexposed, the second would be ok. So, to test this, I switched to burst mode and the underexposed shots had the same Exif info as the correct ones. So I decided my camera had been struck by the problem we're talking about here.
To work around, I switched to Eneloops again and the error went away. But I was concerned that it would eventually show up again even with these Eneloop batteries. So I decided to change the solenoid.

So, I do not think that letting the camera sit on a shelf plays a major part in the development of this problem. But there's clearly a connection to the energy source.

The part I removed form the camera had a green insulator. The part I installed was clear, grey or white (can't remember exactly ;-)), but not green.

The moving part ('horseshoe') of one I removed form the camera was not magnetized at all. It moved smoothly and showed no signs of wear. The force needed to pull it away from the permanent magnet was surprisingly lower than with the part from the laptop.

I didn't investigate this thoroughly, but I think this part works as follows: the permanent magnet holds the moving part/horseshoe in place, while there's a spring connected to the lever inserted into the moving part. The solenoid can either annihilate the permanent magnet's field (counteracting), enabling the spring to pull down the lever, or it can enhance the field to pull the lever back to the resting position. It does this on every shutter release except when using the new eletrical aperture lenses.

So you have three parts in equilibrium: the permanent magnet, the solenoid, the spring. For some reasons, this equilibrium gets disturbed with the green solenoid so that it is no longer able to annihilate the permanent magnet's field. The lever stays in the upper position, because the spring cannot pull it down.

Conjecture: the lever staying up when it shouldn't might cause damage to the aperture block in the long run, which might explain the problems some people here have seen after using the camera a long time after the problem occured. So it might be good to address the problem right away.

Conjecture: the connection to the energy source might point to the solenoid getting out of spec.

Conclusion: While shaving off the horseshoe might put the parts into an equilibrium again, there's a risk that it won't, and also, that the part might degrade further. So, exchanging the solenoid seems to be the way to go, because this makes sure the permanent and electric magnets match each other.

Another conjecture: Putting the poor camera into burst mode and rapidly firing the shutter dozens of times might be doing more harm than good. I'm pretty sure that this means using the camera out of spec and might eventually kill the shutter/aperture motor and/or gears.
If you are stuck somewhere with a hung solenoid, it might be better to try loosening it using the DOF preview, that way, at least the shutter won't be unneccessarily activated.

Finally, regarding this thread: the K-50 is a mighty fine camera, it's light, has good ergonomics, good DR and low-light performance (ISO 3200 is perfectly usable and 6400 is also quite good when using Adobe Lightroom and adding some noise reduction.). As with everything, a complex system might break. Luckily, there's an easy, inexpensive fix.

So I'd like to suggest to some people here, instead of whining and insulting, move on and get over it. Either repair it, get it repaired, or get another camera. But don't make us subject to useless discussions.

'Nuff said ;-)

---------- Post added 02-23-17 at 06:15 AM ----------



I didn't, but I took care to stay away from it's contacts (which is not too difficult). But I didn't take off the top cover, if you do, it might be better to discharge it.

Thank you for the information. I was interested to hear that your issues occurred at the 2-1/2 year mark; some people have suggested that the 2 or 2-1/2 year mark is more a danger time than is any particular shutter-count {at my current rate, my K-30 will reach the 2000 shutter count mark around June, which will also be its 2 year mark}.

[Hutchoman]

Have the same problem with my K-50 after 2 years. I contacted the Consumer Advocate Board here in Hong Kong. The reply that was received from Jebsen's which is the Ricoh dealer in HK, was that there is "no quality problem with the goods". The expected response. HK$900.00 for replacement parts. Was suggested I go to lawyer if wanting to take it further, but what hope does one bloke have. Anyway, will have a crack at repairing the problem myself.

[JoseFF]

So, I'm reporting back, to bring this thread back to its topic. I repaired my K-50 some weeks ago using a donor part from a 15-year-old Samsung laptop CD drive (see here: K-30 / K-50 Aperture Block Failue - Repair Solution available - Page 21 - PentaxForums.com)

The result after about 900 shots: the camera works perfectly. So I consider the error fixed.

Regarding some other statements in this thread:

I've been using the camera on-and-off, partly only once in a month, then again, intensely. Usually, I've been using Eneloop batteries in the adapter cage. Around the beginning of this year (2017), I began using the D-Li109 battery more often. That's when I first saw the error. This was at around 5500 shots and at around 2 1/2 years after I bought the K-50. After powering up the camera, the first shot would be underexposed, the second would be ok. So, to test this, I switched to burst mode and the underexposed shots had the same Exif info as the correct ones. So I decided my camera had been struck by the problem we're talking about here.
To work around, I switched to Eneloops again and the error went away. But I was concerned that it would eventually show up again even with these Eneloop batteries. So I decided to change the solenoid.

So, I do not think that letting the camera sit on a shelf plays a major part in the development of this problem. But there's clearly a connection to the energy source.

The part I removed form the camera had a green insulator. The part I installed was clear, grey or white (can't remember exactly ;-)), but not green.

The moving part ('horseshoe') of one I removed form the camera was not magnetized at all. It moved smoothly and showed no signs of wear. The force needed to pull it away from the permanent magnet was surprisingly lower than with the part from the laptop.

I didn't investigate this thoroughly, but I think this part works as follows: the permanent magnet holds the moving part/horseshoe in place, while there's a spring connected to the lever inserted into the moving part. The solenoid can either annihilate the permanent magnet's field (counteracting), enabling the spring to pull down the lever, or it can enhance the field to pull the lever back to the resting position. It does this on every shutter release except when using the new eletrical aperture lenses.

So you have three parts in equilibrium: the permanent magnet, the solenoid, the spring. For some reasons, this equilibrium gets disturbed with the green solenoid so that it is no longer able to annihilate the permanent magnet's field. The lever stays in the upper position, because the spring cannot pull it down.

Conjecture: the lever staying up when it shouldn't might cause damage to the aperture block in the long run, which might explain the problems some people here have seen after using the camera a long time after the problem occured. So it might be good to address the problem right away.

Conjecture: the connection to the energy source might point to the solenoid getting out of spec.

Conclusion: While shaving off the horseshoe might put the parts into an equilibrium again, there's a risk that it won't, and also, that the part might degrade further. So, exchanging the solenoid seems to be the way to go, because this makes sure the permanent and electric magnets match each other.

Another conjecture: Putting the poor camera into burst mode and rapidly firing the shutter dozens of times might be doing more harm than good. I'm pretty sure that this means using the camera out of spec and might eventually kill the shutter/aperture motor and/or gears.
If you are stuck somewhere with a hung solenoid, it might be better to try loosening it using the DOF preview, that way, at least the shutter won't be unneccessarily activated.

Finally, regarding this thread: the K-50 is a mighty fine camera, it's light, has good ergonomics, good DR and low-light performance (ISO 3200 is perfectly usable and 6400 is also quite good when using Adobe Lightroom and adding some noise reduction.). As with everything, a complex system might break. Luckily, there's an easy, inexpensive fix.

So I'd like to suggest to some people here, instead of whining and insulting, move on and get over it. Either repair it, get it repaired, or get another camera. But don't make us subject to useless discussions.

'Nuff said ;-)

---------- Post added 02-23-17 at 06:15 AM ----------



I didn't, but I took care to stay away from it's contacts (which is not too difficult). But I didn't take off the top cover, if you do, it might be better to discharge it.

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 (1/8 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 1/8 all shots are underexposed.

What do you think? If I look inside the lens when shooting, I see clearly the diaphragm closing down completely in all shots. How come they are differently exposed if the speed and opening are the same? The Exif shows the same data for all of them...

[altopiet]

Hi, I found this, in my MZ-50, which I've already stripped for other parts...The screwdriver points to where I removed it from.

I just want to make sure that it's the part that needs replacement, before starting to strip my K-30.

(Sorry about the cellphone quality)

[sys3175]

Hi, I found this, in my MZ-50, which I've already stripped for other parts...The screwdriver points to where I removed it from.

I just want to make sure that it's the part that needs replacement, before starting to strip my K-30.

(Sorry about the cellphone quality)

It surely looks like it. To make sure, you should compare the coil's resistance after you removed the other part, they should be roughly the same.

So they already used it in the film era. Further proof that the mechanism by itself is not the culprit, but solely a faulty component.

[madphys]

I just want to make sure that it's the part

That's the one - you have removed it exactly from the aperture control mechanism on the MZ50 - the mechanism hasn't changed substantially over the years btw.
I suppose it will be a direct replacement.

[altopiet]

It surely looks like it. To make sure, you should compare the coil's resistance after you removed the other part, they should be roughly the same.

So they already used it in the film era. Further proof that the mechanism by itself is not the culprit, but solely a faulty component.

Will try the change this coming weekend....