[BugsDogsAndSunsets]

My K-30 started having issues when it was almost exactly three years old, but I had been running it on the AA-adapter available for K-30 and K-50 bodies, which seems to prolong the life of those, so timing sounds about right to me. If your camera is beginning to develop aperture control issues, it will happen gradually - initially the first photo each day, then two, etc. The best way to postpone permanent and total issues seems to be to use the aperture control every day, so I doubt very much that "using it alot more" will speed up the problem - in fact, that is more likely to delay the problem. If you read photos {dark frame followed by normal exposure} into editing software, such as PhotoShop or gimp, the dark frame should have the histogram squeezed into the left end {but still a curve} while the normal exposure histogram should look totally normal indeed.

Yeah, I think the problem isn't that I'm using it a lot more, but rather that it sat for 6 months without use until recently.

Yesterday I was able to replicate it twice, but this morning on a different lens it didn't happen. I'll keep a close eye on it (and will check the histograms as you suggest).

If it keeps up on multiple lenses, I may opt to fix before it gets worse. Intermittent issues like this would drive me nuts, even if they're not really an impediment to practical shooting. I'm pretty handy with a soldering iron, so the fix doesn't look too arduous.

[reh321]

Yeah, I think the problem isn't that I'm using it a lot more, but rather that it sat for 6 months without use until recently.

Yes, often a report made here would begin something like, "I took my K-50 off the shelf {where it had sat for some months} to take photos at my son's birthday, and it gave dark images".

[The Squirrel Mafia]

Excellent work here!

[17dew]

Thanks for the detailed description and photos! What would be your recommendation for a precision soldering iron/station? Thanks again

[photogem]

I like Ersa and Weller very much, but prefer Ersa.

The most important is the thin pencil-tip!


that's why I prefer Ersa, their tips are very thin and nice long

15W for an non-regulated or max. 20W.

And then low-temperature melting solder

[17dew]

What would be your recommendation for a precision soldering iron/station? Thanks again

I like Ersa and Weller very much, but prefer Ersa.

The most important is the thin pencil-tip!


that's why I prefer Ersa, their tips are very thin and nice long

15W for an non-regulated or max. 20W.

And then low-temperature melting solder

Thanks,Ill check out the Ersa!

[photogem]

I use this tip:
amazon.com: Ersa Ersadur 0832UD Long-Life Soldering Tip 0.4 mm Straight Extended Pencil Point Tip by ERSA: Gateway?tag=pentaxforums-20&

good are:

Ersa Analog 60 soldering station (and any other)

Ersa 15+ universal soldering iron (15W)

[photogem]

Added another photo showing the diaphragm control block without solenoid and refining some parts.

[BugsDogsAndSunsets]

I've got a white solenoid on order from Ebay, and in the meantime I've done more testing and reading. My camera definitely exhibits the behavior of stopping down when the aperture is wide open on the first shot after a rest of 30 minutes or so - observed on 1 second exposures at f 1.4.

I read that this should have been fixed at some point during production (K-s2), but my camera was manufactured 2016-12-08. Do we have any more information about what other models might become affected in the future? I assume the higher end bodies are different enough to escape the issue, but couldn't find anything definitive on the subject.

[photogem]

There is nothing definite to be found. According to member Tonytee we guessed that in Dec. 2015 changes where done but we have no definite information.
As very few K-S1's + K-S2's were reported to have failed (for the K70 it is too early) I strongly suggest something as done. We also must take into account that those few reported ones did stir up much more than then the K-30 or K-50 due to the fact that "oh... not again"! Only very few K-70's had been reported in Europe, actually Germany only. So this is within the percentage were things happen/go wrong anyway, nothing dramatic. And for those (you in this case) affected might find it dramatic. And yet, the solution is there and if you follow instructions with care not only is your Pentax "up to date" and will not have this problem anymore (because the made in Japan never failed, exept ... as we soon approach Easter... one might find one made out of chocolate instead of teflon).

[reh321]

I assume the higher end bodies are different enough to escape the issue, but couldn't find anything definitive on the subject.

Yes, the higher models - K-7, K-5, K-3, K-1, KP - use a stepper motor, an entirely different mechanism, instead of a solenoid.

[photogem]

On ebay these days there is a glut of green Chinese solenoids . I had to buy one because I wanted to know about it:


You can see very clearly this is not even the same one as the green China-Solenoid built into Pentax cameras!
It has no contact-pins to the side, just to the front! Meaning you've got to solder where this very thin and fragile copperwire of the coils is soldered to.

But it is not only those 2 missing pins which make it critical to built in:


The holding force is also too strong.

So beware!


This picture shows this thin wire soldered to the side-pins on the original green solenoid which was taken out from a Pentax K30.

[BugsDogsAndSunsets]

I just finished following these steps on the K-S2. Everything went pretty smoothly, and I got everything back together with minimal fuss (and no missing screws!)

There was one tiny bronze colored bushing/washer thing which fell out at the last minute, and I wasn't sure quite where it should go - almost certainly around one of the screws, but I wasn't sure which one.


The aperture issue appears to be solved - no stopping down on the first frame wide open. I also tested some rapid fire shots, and everything seems to work fine, but there's one problem I wanted to ask about.


When I tilt the camera back and forth (like the motion you would make to shoot in portrait orientation, but both directions), there's an audible and perceptible shift of something inside the camera. It's totally possible that this was present before, but I don't recall anything like it.


I can post pictures of the procedure tomorrow (still uploading from phone), and I can see if a video can capture the sound (it's pretty subtle, felt more than heard, like something sliding back and forth).


Any thoughts?

[MarkJerling]

I just finished following these steps on the K-S2. Everything went pretty smoothly, and I got everything back together with minimal fuss (and no missing screws!)

There was one tiny bronze colored bushing/washer thing which fell out at the last minute, and I wasn't sure quite where it should go - almost certainly around one of the screws, but I wasn't sure which one.


The aperture issue appears to be solved - no stopping down on the first frame wide open. I also tested some rapid fire shots, and everything seems to work fine, but there's one problem I wanted to ask about.


When I tilt the camera back and forth (like the motion you would make to shoot in portrait orientation, but both directions), there's an audible and perceptible shift of something inside the camera. It's totally possible that this was present before, but I don't recall anything like it.


I can post pictures of the procedure tomorrow (still uploading from phone), and I can see if a video can capture the sound (it's pretty subtle, felt more than heard, like something sliding back and forth).


Any thoughts?

I doubt you have anything to worry about. It's probably the SR system. See: My Pentax DSLR makes a rattling noise - is it defective? Something is loose inside! - PentaxForums.com

[BugsDogsAndSunsets]

I doubt you have anything to worry about. It's probably the SR system. See: My Pentax DSLR makes a rattling noise - is it defective? Something is loose inside! - PentaxForums.com

Just after I posted I noticed it diminished when the SR system was active... phew! I was on ultra high alert since I'd just disassembled such a precise instrument. Thanks!!