[rogerstg]

Sitting on the shelf for a year is deadly for it.

Had to have my K-S2 Aperture Control block replaced as well. The camera was new, but had set in the box for a year or so and not been used when the problem occurred.

I hope that's not the case, but if it is, I suspect Pentax will be repairing all the old stock being sold on special now. I recently bought one for my wife, which according to the metadata tool, was manufactured on March 22, 2017. That's more than two years sitting unused.

So far so good after only about a hundred shots.

[reh321]

I hope that's not the case, but if it is, I suspect Pentax will be repairing all the old stock being sold on special now. I recently bought one for my wife, which according to the metadata tool, was manufactured on March 22, 2017. That's more than two years sitting unused.

So far so good after only about a hundred shots.

'We' do not understand the process of one of these cameras failing. Anecdotally, many stories of failure begin something like "I took my K-50 off the shelf where it had sat for six months to take photos of my child's First Communion and the photos were all dark". I was trying to encapsulate that sort of thought.

On the other hand, I purchased my K-30 from KEH at a time when I had never heard of the Dark Image Syndrome. My camera had a shutter count of 3 when I got it; I used it for about three years on AA batteries before it started failing. I am sure that a New In Box K-S2 purchased in June 2018 will be no more failure prone than it would have been when purchased the day after it was produced, but I would make a point of using it regularly after that.

[rogerstg]

'We' do not understand the process of one of these cameras failing

Thanks for encouraging words, and I should have used some emoticons since I didn't mean to indicate that I was worried. I understand that the helpful comments are the result of anecdotal evidence and worthwhile within that context.

[totsmuyco]

Actually it scared me off buying one last week. Like I said, the k-s2 has a very good feedback except for this problem. The errors on the d5300 as far as I've read is I think even worse. It can't focus properly.

[reh321]

A thread in the K-70 area is very relevant here.
Solenoid in Pentax K-70 - PentaxForums.com

Member @photogem; compared the solenoid used in the K-30/50 with the one used in the K-70 {and presumably in the K-S2}
The following summarizes his conclusions

To me it is very clear, Ricoh did demand a modification of the plunger. The modification worked because very few K-S1 and K-S2 failed, we don't know yet about the K-70 but I am positive that we will have only very few failures.

And yet, some did fail. So a very precise modification to the plunger similar to very precise sanding and polishing did bring success but not yet 100%

[photogem]

... and presumably in the K-S2

It was the solenoid from a K-S1, but I had repaired the K-S2 as well, just that then I didn't realize how important closer inspection of the solenoid would be.
Which I will repeat one day.

[rogerstg]

Actually it scared me off buying one last week.

That's too bad.

My way of looking at it is that (adjusted for survey bias) the failure rate for the worst models (K-30/50) is only ~6% based on a 2016 survey. Pentax didn't even know that is was a problem until late 2015, so probably not addressed until early 2016 at the earliest. Most of the production for the K-30/50s was before the problem was identified and definitely before the survey was taken. So 6% for aperture control failure overall is the worst case, and probably by a lot.

For the K-S2, the surplus production is likely to be the latest production, after the problem was addressed. For me, it turned out to be correct since mine was produced 3/2017. Additionally, we have some anecdotal evidence that non use leads to failure of defective solenoids. To my mind, sitting on a shelf for 2+ years is a pretty good test of that. If it works out of the box, it already passed the test and you have a good one. If not, you can get it repaired under warranty.

I see very little risk (knocking on wood).

[photogem]

My way of looking at it is that (adjusted for survey bias) the failure rate for the worst models (K-30/50) is only ~6% based on a 2016 survey

I don't think so. I have closely watched offers on eBay and other 2.nd hand platforms. I think with the K-30/50 it was higher than 6%
In the German Pentaxianforum the survey failure rate for the K-30 was actually 65%! 40% for the K-50.

I don't think those figures are acurate either, too high, but 6% is way too low. The survey showed that mainly long-time members of the forum voted.

Pentax didn't even know that is was a problem until late 2015, so probably not addressed until early 2016 at the earliest. Most of the production for the K-30/50s was before the problem was identified and definitely before the survey was taken.

They must have know way before because designing/developing the new "diaphragm control unit" and then having it built will take at least 6 month of not longer!
It was in December 2015 when the first changes were applied to the K-50. I know a person who purchased the first new "diaphragm control unit" April/May 2016.
Then it was already in regular production and put in into K-30/50/500 under the 2 year warranty in the EU and Switzerland! It was later on when they realized it was NOT the complete "diaphragm control unit" but only the solenoid which was faulty, from then on when they repaired it, in most cases it was solely exchange of the solenoid itself!

For the K-S2, the surplus production is likely to be the latest production, after the problem was addressed. For me, it turned out to be correct since mine was produced 3/2017. Additionally, we have some anecdotal evidence that non use leads to failure of defective solenoids. To my mind, sitting on a shelf for 2+ years is a pretty good test of that.

Possibly a good test, yes. I never stopped people buying the K-S1 or K-S2 but recommended it. But I told them that there was a tiny chance this could happen...
and that then ... in any case... I could and would help.... of course.

[Angulon]

A follow up report - previous posts were #s 76, 80, 86, 98. Regarding a ex warranty repair, well my K-S2 is still going good,
although not used that regularly, still takes great photos when used right .

[Benz3ne]

Interestingly, I've a K-S2 which I've used very, very lightly over the last few years with a sharp increase in use recently. It's now almost exactly 3 years old. It has, at times, sat for 6 months or more and I've seen no issues yet (touch wood).

[reh321]

Interestingly, I've a K-S2 which I've used very, very lightly over the last few years with a sharp increase in use recently. It's now almost exactly 3 years old. It has, at times, sat for 6 months or more and I've seen no issues yet (touch wood).

Remember that every camera is different. Evidence is that the average K-S2 body will give many years of good service and never have aperture control issues of any sort.

[elpavorealduos]

so i did the repair as described here: Re: K-S2 Aperture block failure repaired: Pentax SLR Talk Forum: Digital Photography Review
it worked fine but not my manual focus won't work. i can switch to auto or manual but it stays in auto all the time. anyone has any idea what i might have done?

[photogem]

so i did the repair as described here: Re: K-S2 Aperture block failure repaired: Pentax SLR Talk Forum: Digital Photography Review
it worked fine but not my manual focus won't work. i can switch to auto or manual but it stays in auto all the time. anyone has any idea what i might have done?

Yes, you didn't align the inner part of the AF-M switch with the outer. It is stuck.
You have to open it again and check.

See here:
Manual: Solenoid replacement: Pentax K-S1 - PentaxForums.com

Here you can see the inner part of the AF-M switch of the K30:
https://www.pentaxforums.com/forums/members/85274-photogem/albums/13024-sole...ture127300.jpg

and here is a photo of the inner part of this switch of the K-S2:
http://h2097500.stratoserver.net/forumimages/2018/5330/5330_2018031851_11.jpg

You check that the inner and outer part of the AF/M-Switch are on AF:
The inner part is on AF when the screw-drive gear in this small hole in the metal K-bajonett is "peeping out!

But it was a bad idea to do the sanding-grinding!
It is prone to fail again.

See here:
https://www.pentaxforums.com/forums/151-pentax-k-30-k-50/385045-manual-solen...ml#post4684425

here:
https://www.pentaxforums.com/forums/151-pentax-k-30-k-50/315725-dark-exposur...ml#post4645513

and here:
https://www.pentaxforums.com/forums/151-pentax-k-30-k-50/388728-why-you-shou...t-replace.html

[photogem]

@elpavorealduos:
If something goes wrong during such a repair it would be very useful to know if you were able to solve the problem?

Very important for other DIYers!

[photogem]

Before my last message send a pm to member elpavorealduos and asked him if he was able to solve the problem. He answered:

Yes, thanks. I opened the camera again and moved the plastic bit to adjust the switch and works fine now!

I then asked him to post this here.

But no reply anymore.

We are a forum, i.e. something like a community and we try to help each other.

As I mentioned before, such situations are very important for DIYers because we learn from making mistakes.