[Martin Stu]

Photogem, since you are monitoring my posts, you should see that the word "recommended" is not there. I told you about my successful experience... at the same time, I pointed out that I didn't know how long the normal operation would last... since you are tracking my messages, you should know that after my repair, the problem has not been repeated for more than 8 months (if it happens, I will definitely tell you)
I am again surprised to read:
Photogem,

And although I know you use Eneloops, this was not what helped you!

But I don't use Eneloops!

[photogem]

Photogem, since you are monitoring my posts...

I am not monitoring your posts. I knew you wrote commentaries on the solenoid at times.

Otherwise I would have noticed the contradictions earlier on.
I happened to read this earlier message of yours (mentioning the video on YouTube) by chance because I was searching for something different.

....you should see that the word "recommended" is not there. I told you about my successful experience...
at the same time, I pointed out that I didn't know how long the normal operation would last...

Yes, but that was recently

since you are tracking my messages.....

again: I am not tracking your messages. I just found it by sheer accident.

...you should know that after my repair, the problem has not been repeated for more than 8 months
(if it happens, I will definitely tell you)

But I don't use Eneloops!

o.k. maybe not Eneloops, my memory evaded me.
But you use batteries with the AA-Adapter. That is the same, because there is more current available:

Reread THIS earlier post of yours that might help.

[Martin Stu]

o.k. maybe not Eneloops, my memory evaded me.
But you use batteries with the AA-Adapter. That is the same, because there is more current available:

I wrote to you that I do not use AA batteries, Eneloops (or any others). I am using the supplied D-LI109 battery.

Thanks for finding my post Reread THIS earlier post of yours, as you may have noticed with your discerning eye, my post has been edited, this was my reasoning (thoughts) based on user posts.

[photogem]

I wrote to you that I do not use AA batteries, Eneloops (or any others). I am using the supplied D-LI109 battery.

Thanks for finding my post Reread THIS earlier post of yours, as you may have noticed with your discerning eye, my post has been edited, this was my reasoning (thoughts) based on user posts.

Sorry but then I don't understand and maybe it is a problem of communication or language.
You wrote:

I have the same problem (ABF) with the K-30,
unwittingly suggests a conspiracy of the manufacturer
when I use the adapter with batteries, the problem disappears

How I understood this was that your K30 develobed ABF and you then used the AA-adapter
which is with AA-batteries and the problem then disappeared.

That's how I understand your message but please correct me if I am wrong!

This approach is well known, it worked for many (at least a short time).

But maybe your post was a question and you forgot the question-mark?
Then of course this would change everything.

---

Last edited by photogem; 05-05-2021 at 08:53 AM.

[Martin Stu]

Sorry but then I don't understand:
You wrote very clearly:

yes, yes, you are right, I seem to have made a typo ... but that’s not the point, the point is that after repairs for more than 8 months I have been using the camera on my own battery D-LI109 and this problem doesn’t exist

[a200user]

Update on my K30 Solenoid 'Fix'

Referring to my post #338 last April 24, 2020. I had opened up my K30 that had the Auto Aperture solenoid problem, pulled the horseshoe magnet out, made sure it was clean and put it back together.
It worked again.

I am happy to report that my K30 is still working perfectly for over a year now. The only thing I have done differently is to use the K30 at least once per week. I relate the original problem to a lack of use for over 3 months.

EDIT: For a point of reference I had reported in April 2020 that my K30 had a shutter count of about 5300. The last photo I took today was shutter count 6410. So since my 'fix' I have had about 1100 shutter releases without a problem. Granted, that is not a high shutter count for a year of use.

Thanks for taking the time to document how to access the solenoid.

EDIT MAY 6, 2021 (21:56 EDT USA). I did not change or alter the 'green' solenoid in my K30 in any way. Therefore no one should conclude that simply removing the "U" plunger and inserting it back into the body will result in a permanent fix. My previous posts #338, #340, #346 indicated that I expect it to fail again since it is still the same faulty solenoid that will likely fail again.

[photogem]

I had further direct communication with Martin Stu via PM and I think we solved it, misunderstandings mainly due to language.

Martin "polished" the plunger of his solenoid but then demagnetized it as well not really thinking the demagnetizing would help.

The plunger demagnetizes if one just removes it from the main body/permanent magnet! Any magnetism very quickly disappears completly, nothing can be measured anymore. But as soon as the plunger is back in the body it will magnetize right away!

Also the metal-body itself will stay magnetized:



And yet, in rare cases this can work as it did with member "a200user".
But mainly because he used his K30 on a regular basis.
Too bad if his K30 would stay unused for another few weeks: ABF would return at some point.

In a way this solution is more or less similar to what is done by the official repair places: They just replace the solenoid with the same China-Version, very often the problem returned. Those who paid $ 250 or similar then feel rightly let down.
I have myself repaired enough Pentax bodies after exactly this happened and I know of further cases.

That is why recently I chose to let go not to recommend the sanding/filing method at all because those who cannot apply DIY
and won't find anybody doing it for themselves have the choice to send their Pentax to PC35 Photo Lab (now Pentax Camera Repair) because they inofficially give warranty beyond their official 1year warranty, which then for $100 + shippingcosts is a reasonable deal and better than a non-working (or castrated M-Mode) Pentax!


When we discuss the correct technique how to take photos we will not discuss AUTO or SCN modes, don't we!


We will discuss Av, Tv, Tav, P or M mode!

Nobody would even dare to recommend AUTO!

In rare cases maybe SCN.

But even then we better recommend P-mode which can be used as an advanced AUTO-Mode with ability to learn Av or Tv.

And so it is with repairing the solenoid!

- Removing the plunger or worse by greasing it is similar to AUTO-Mode (i.e. a childish way of using a DSLR)
- Removing the plunger and sanding/polishing it is similar to SCN-Mode (a bit advanced, a little bit more effort)
*polishing might even be better than sanding or chamfering because the surface is not destroyed.
More in the sense that a smoother surface can glide better or course.
So that might be the secret of Martin Stu's success.

I tried it a different way by drilling 1mm holes into the plunger and closing them with epoxy.
It worked but you need a precision drilling machine for that which I have. It must drill very precise and not be too hot
because otherwise the plunger will burst!


If one is lazy or unable to learn other modes and choses to use AUTO..... fine!
But you wouldn't make it public, recommend it to others.

You wouldn't consider up-loading photos here taken in AUTO-Mode.

And as much so you shouldn't make it public if you chose just remove the plunger!
WHY?

Simply because it can mislead others, can lead to some wishfull thinking with the danger of disappointment.

PLUS: Having to disassemble the Pentax again means for sure that the plastic threads of some screws are hurt more, screws might not hold tight anymore. Particular if it is the screw holding the solenoid which is a part with strong powerful movement.
You don't want to mess around with larger screws there.

The problem then is that one is forced to use Expoxy!
Those plastic threads are just not made for that.

What I really don't understand is when somebody who has the skills to solder etc. has taken on the task to disassemble his Pentax
Unscrewing the solenoid but letting it dangle on the 2 wires and then to remove the plunger is not only 99% of the work done
but actually more critical due to the short wires than actually unsoldering it.

And then for making sure that ABF doesn't return once a week some shots?
That's fine, one can do it. I am not critizising that.
I am critizising to make it public!


Kind of "I know how to use Av, Tv, Tav etc. but I am lazy and will just use AUTO"
Nobody would take that serious!

---

Last edited by photogem; 05-06-2021 at 08:41 AM.

[a200user]

Wow, photogem, quite a lengthy critique.
You struck a nerve with me so I will address a few points:

It's not an inconvenience for me to use my K30 on a regular basis. You're not criticizing that, but I shouldn't make it public? It seems that lack of use is common to those that have reported failures. What's wrong with 'use it or lose it' posts in public? Like this quote from a famous member "It is known and proven that a very regular use usually helps, in a way you could say leaving a car standing all the time unused is not that good for the pistons. Mechanical parts designed for movement are better used." It should sound familiar to you, see your post #347 on pg 24.

The solenoid wasn't dangling on the 2 wires, I had it supported appropriately during the 'procedure'. It's not like it is a boat anchor hanging by a thread.

My post #338, pg 23, explains why I didn't do any soldering. I don't trust my soldering skills enough to wreck a working K100D on a potentially dead K30.
(My post #348 pg 24, indicated my level of soldering skills, you even responded to it)

In my post #340, pg 23 I said that I didn't expect what I did to work. And having working K100D, K20, and K5 IIs I decided not to put any money or any more time into the K30. I also indicated my pleasant surprise that it worked after putting it back together and I also said that I expected it to fail again sooner or later. (see my post #346 pg 24). Why do you seem to imply that I am endorsing what I did as the solution when I said more than once that I expected it to fail again? Does that sound like I am misleading anyone?

Speaking for myself, I know enough about solenoids having worked on cassette and reel-to-reel tape decks that I wouldn't lubricate or sand, I never said that I lubed or sanded. Why do you imply that I did?

Again, I have to thank you for the work you have done, but you seem to be offended by anyone that even 'temporarily' solved their ABF problem without doing it YOUR way, calling them lazy, implying they are misleading others and further implying they did things (lubricating, sanding) that they did not.

I'm sorry that I feel offended by your remarks, I just reviewed the last few pages of this thread and see that you are not singling me out, I guess it's just your style: (see post #345 at the bottom of pg 23.)

[photogem]

It's not an inconvenience for me to use my K30 on a regular basis. You're not criticizing that, but I shouldn't make it public? It seems that lack of use is common to those that have reported failures. What's wrong with 'use it or lose it' posts in public?

I never ever questioned that one should not use the camera on a regular basis but as you know always the very opposite.
I find it inconvenient to keep a K30 as a backup but "having to use it" just to prevent the solenoid getting stuck. But that is just my view.

Being critical of making this kind of method public has two very different reasons!
One I had already explained:
1) my comparison of AUTO vs. Av/Tv/Tav/P/M-modes (again, just my point of view)

The other reason I intentionally didn't bring up, but now I see I was mistaken: It is important:
2) One has a responsibility with recommendations, because such a recommendation made puplic it acts as an example!

Look how many views this very thread got! I didn't first bring up this concern because I didn't want to give ideas.
Same way I hesitate to recommend swapping solenoids from the flash-section of an older Pentax with Japan-Solenoid with the green China-Solenoid. Because twice I purchased broken *ist-DL's for the solenoid but found green ones inside. Swapped but not mentioned.

If I recommend methods which can go wrong but are very cheap those recommendations can serve others to repair their cameras that way and then sell it in "working condition".


I have seen offers on ebay with such claims (I don't mean an official repair which would be with an invoice or at least some other paper if on warranty)
Because I had received such cameras for repair to find out that they had a "manipulated China-Solenoid inside" but failed again, I started to ask questions to sellers how their repair was done. Answers very dubious. Im most cases they had been sanded of course.
The most common trick.

So bringing up such solutions which are not save (and they are for sure not safe if the camera is not used for a longer period which does happen a lot) has the potential of misuse and thus others have the harm.


Now, to go further into the method which you recommend:
A German blogger named Florian Mai recommends exactly the same method:
Pentax K-50 Blendenfehler „reparieren“ ? florianmai.de
There are only 7 commentaries left:

2 commentaries mention success
2 commentaries are neutral, questions but the person did not do it
3 commentaries are critical. One person I know of, Mr. Goldbach, an engineer from near Frankfurt, well known for Pentaxrepairs.
He and the other two had problems with the method and explain why.

There had been more critical commentaries, one I wrote, but all those had been deleted. Pride?
Waybackmachine-search wasn't successful

The solenoid wasn't dangling on the 2 wires, I had it supported appropriately during the 'procedure'. It's not like it is a boat anchor hanging by a thread.

But the danger of damage is as high as just unsoldering the two wires from the still screwed in solenoid!

My post #338, pg 23, explains why I didn't do any soldering.
I don't trust my soldering skills enough to wreck a working K100D on a potentially dead K30.
(My post #348 pg 24, indicated my level of soldering skills, you even responded to it)

I do remember that but you indicated as well that if the problem would come back, you'd give it a go (at least that was my impression)
You have replaced tiny transistors in a Teac Open-Reel-machine. To me that sounds skillful enough. And you have this great professional Weller soldering station, better than the Ersa I use. One of the best for the money with fantastic tiny soldering tips. I plan to buy the almost similar Weller WS81.

Speaking for myself, I know enough about solenoids having worked on cassette and reel-to-reel tape decks that I wouldn't lubricate or sand, I never said that I lubed or sanded. Why do you imply that I did?

I didn't imply that, I know you didn't sand nor lubed. This was a general answer, I didn't mean you!

Again, I have to thank you for the work you have done, but you seem to be offended by anyone that even 'temporarily' solved their ABF problem without doing it YOUR way, calling them lazy...

No, I didn't call them (nor you!) lazy. I wrote:

If one is lazy or unable to learn other modes (i.e. Av, Tv, Tav etc.) but choses to use AUTO..... fine!
But you wouldn't make it public, recommend it to others.(?*)

*I meant this as a question and forgot the questionmark and it was related to taking photos in AUTO-Mode
I apologize for not making that clear so it could be misunderstood. Again, no offence meant.

... implying they are misleading others and further implying they did things (lubricating, sanding) that they did not.

That is wrong: I wrote "it can mislead others". Which I think is true: Particular for those leave their cameras unused for a longer period and more so if those who think they can repair their Pentax that way and then sell it as fully functioning, maybe even with an added "ABF repaired".

I'm sorry that I feel offended by your remarks, I just reviewed the last few pages of this thread and see that you are not singling me out, I guess it's just your style: (see post #345 at the bottom of pg 23.)

I am sorry you felt offended, I didn't mean to offend you at all!

If you re-read post #343, you might very quickly realize that then I responded to a person whose photos I admire but who tried to teach me some (totally wrong) "lesson 101 in magnetic theory". He early on had recommended degaussing which is very dangerous with the solenoid inside the camera. Even degaussing just the plunger won't be useful. His "lesson 101" was just sheer nonsense!
The solenoid works exactly the opposite way he thought it would work: In 99% of its time the plunger sits near the magnet and gets magnetized. So if somebody wants to teach me his "lesson 101" which is based on quicksand I point at that quicksand and who might be stuck in it. Single-lens-reflex!
Maybe my style isn't that convenient, yet... English isn't my native language although particular through writing in this forum I got some good practice. But I have to check again and again how a word is spelled, make use of the dictionary and often correct later again because mistakes slipped in. I tried writing first w. MS-WORD (because there I have a correction facility) but copying and pasting does not work here, distances between words change. No matter if I use my PC or my Laptop.

It is so easy to point the finger at the obvious but the elusive obvious is not that easy to figure out:
What can happen and had happened a few times you can read HERE and the result looks like THIS
Then you have to work about 10-20hours to completly take your K30 apart to get the diaphragm-control-block out.

[a200user]

This morning I realized that I haven't used my K-30 in sometime, maybe 2 or 3 months as my wife was going through a terrible health crisis that required brain surgery in January.
Thank God that was successful and we are getting back to normal. Anyhow I got the K30 out and took some quick shots fully expecting the dark exposure Poltergeist to have returned due to lack of use.
But to my pleasant surprise it's still working fine.

Terrible composition on this photo, Exif: Pentax K-50 (It's actually a K-30 but I did the hack to bring it up to the K-50 firmware), Av mode, F7.1, ISO 400, Pentax SMC DA !:4 16-45mm ED-AL Lens, 24mm, on board flash.
No post processing except to resize, just to show it still works.


I did the non-recommended fix in April of 2020 so it's been almost 2 years. I feel blessed that mine is still working. "Even a blind squirrel finds a nut once in awhile".
Come to think of it, I will be married 50 years in April too. Yes, I am a very blessed man.

[photogem]

This morning I realized that I haven't used my K-30 in sometime, maybe 2 or 3 months as my wife was going through a terrible health crisis that required brain surgery in January.
Thank God that was successful and we are getting back to normal.

Indeed, a great success!

Anyhow I got the K30 out and took some quick shots fully expecting the dark exposure Poltergeist to have returned due to lack of use.

That could have very well been the case.

But to my pleasant surprise it's still working fine.

Which is one of the rare exceptions.
I know of a person who has 6 Pentax DSLR's with his family, all with the China green solenoid.

Three of them on warranty repair:
One of them failed again after the same solenoid got stuck again
Two had a special modification to the solenoid which I think is the best but those two failed as well after the warranty for the repair was over. The other three failed outside warranty. He loves Pentax and sticks with it aside of those problems.

Terrible composition on this photo, Exif: Pentax K-50 (It's actually a K-30 but I did the hack to bring it up to the K-50 firmware), Av mode, F7.1, ISO 400, Pentax SMC DA !:4 16-45mm ED-AL Lens, 24mm, on board flash.
No post processing except to resize, just to show it still works.

Well, I recognize some vintage audio-gear, Tandberg reel-to-reel and tapemachine, together with Nakamichi and Revox some of the very best.

I did the non-recommended fix in April of 2020 so it's been almost 2 years. I feel blessed that mine is still working. "Even a blind squirrel finds a nut once in awhile".

It wasn't actually a real fix although some might call it that way.
In a way it is the opposite, to get something lose that is too strongly fixed/stuck.

But you know, most who do for example the filing/sanding job know it can come back, so they do it and sell it then.
So we won't know about it when the problem returned.
I know because quite a few of those landed on my work-bench. They buyer purchased it in good faith and luckily then
started to search about the problem. But I am certain: Most are just thrown away.

Come to think of it, I will be married 50 years in April too. Yes, I am a very blessed man.

Well done, I think a working marriage is something that can be of great support in such difficult times.
Well.. first we had Covid which now is peanuts compared to what happens in Ukraine.

[Andrewjgw]

Hi new to the forum, and while trying to find a solution, I am quite impressed with the knowledge base here.
I have a KS1 which I bought about 6 mths ago, used with a 5500 shutter count, since which I have taken some 7000 images. However, since purchase it had a very annoying habit of taking completely black (servely* unexposed) images randomly. Unfortunately it still does that during a photo session, one frame each time but It's has developed further in that in that every time before I* start a session, either a few shots or a days worth of shooting the camera takes many 'black' images before it starts to take correctly exposed shoots and even then it will underexpose a few shoot until it 'finds' the correct level. It currently, i have to take 40 or 50 black images (changing mode and settings) before it corrects itself but more often it can take up to 200 shots before it starts to work. It is like the camera has to warm up, before it starts to work. The final straw was a trip to the zoo, and all day it was completely under exposing all photos (I took some 300 photos trying to 'warm it up) but had to set the iso 1600 and ev +5 to get an acceptable image. However it did have a good exposure when taking video!! I have upgraded the firmware to 1.2 and the lens does not seem to have an effective. Did contact Pentax but chocolate teapot comes to mind.
I am really enjoying my photography but this is spoiling it.
I would really appreciate some help here. Thanks, Andrew

[photogem]

Hi new to the forum, and while trying to find a solution, I am quite impressed with the knowledge base here.
I have a KS1 which I bought about 6 mths ago, used with a 5500 shutter count, since which I have taken some 7000 images. However, since purchase it had a very annoying habit of taking completely black (servely* unexposed) images randomly. Unfortunately it still does that during a photo session, one frame each time but It's has developed further in that in that every time before I* start a session, either a few shots or a days worth of shooting the camera takes many 'black' images before it starts to take correctly exposed shoots and even then it will underexpose a few shoot until it 'finds' the correct level. It currently, i have to take 40 or 50 black images (changing mode and settings) before it corrects itself but more often it can take up to 200 shots before it starts to work. It is like the camera has to warm up, before it starts to work. The final straw was a trip to the zoo, and all day it was completely under exposing all photos (I took some 300 photos trying to 'warm it up) but had to set the iso 1600 and ev +5 to get an acceptable image. However it did have a good exposure when taking video!! I have upgraded the firmware to 1.2 and the lens does not seem to have an effective. Did contact Pentax but chocolate teapot comes to mind.
I am really enjoying my photography but this is spoiling it.
I would really appreciate some help here. Thanks, Andrew

Hello Andrew and welcome to the forum.

You question is in the wrong section, it should be in the K-S1/ K-S2 section and not K30/50.

Anyway, this is the only solution:
Manual: Solenoid replacement: Pentax K-S1 - PentaxForums.com
i.e. you need to find the true DSLR Japan solenoid and be careful, on ebay UK there is a seller (randr.2012) who sells white Japan solenoids but they are SLR from filmcameras.
Why you don't want to use those is explained in all detail here:
A LITTLE BIT OF HISTORY: Development of the solenoid in Pentax cameras - PentaxForums.com

But there is a good solution for you: John Pye in England sells the correct new version China-Solenoid in UK for £9 plus 20%VAT
so it is cheap. But you need to dare to take on the work:
https://www.johnpye.co.uk/john-pye-technical-services/

Read here:
https://www.pentaxforums.com/forums/151-pentax-k-30-k-50/321871-k-30-k-50-ap...ml#post5544332

[randjmarsh]

Try this procedure in the link below - worked for my K50.

my fix of the K-30 aperture problem without disassembly: Pentax SLR Talk Forum: Digital Photography Review

[photogem]

Try this procedure in the link below - worked for my K50.
my fix of the K-30 aperture problem without disassembly: Pentax SLR Talk Forum: Digital Photography Review

The OP of this thread posted the same idea HERE in this forum, but we already had developed better, though more expensive approaches.

This is what can happen if one follows this advice:

And if you know about it you can see, this was already China-Solenoid-Generation-2 (KS-2 and early K-70)

I.e. the version which came after Dec. 2015.

In all K30's and most K-50's you have solenoid Gen.-1 with the stronger magnet, so the plunger gets more magnetized and thus an advanced danger

of this "sledgehammer missing": Invitation for total exodus!


The reason is that it brings stress onto the stuck solenoid because the origin of the problem is not solved.
It is a bit a sledgehammer method. It can work but it won't solve the problem because the magnetism of the plunger will return without any daubt:
See here, it is all explained in all detail:
A LITTLE BIT OF HISTORY: Development of the solenoid in Pentax cameras - PentaxForums.com
I even would rather recommend the filing method (which those who know me know that I discourage this method!)

The best approach is to change the solenoid with the DSLR Japan solenoid:
https://www.pentaxforums.com/forums/151-pentax-k-30-k-50/385045-manual-solen...id-choice.html

UK Members can contact John Pye and get the China-Solenoid Generation III which works well.
I still prefer the Japan-version