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Forum: Pentax K-S1 & K-S2
10-09-2020, 11:52 PM
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Did you meanwhile transplant the white Japan-solenoid from the flash-circuit of your K100D into the aperture-control of your K-S2 and the green China-solenoid
into your K100D (flash)?
It should give you 2 working Pentax bodies without any loss because the green China-Solenoid is less "stressed" in this very simply flash circuit of the K100D.
It works similar as in DVD drives, just a push on the flash-release button brings 7.2 Volts to the solenoid via a very simple transistor protected by a diode.
You just have to be careful, there is a tiny plastic rod connected to the mechanism in the K100D which pops out about 1,5cm behind the metal hook which holds the pop-up flash closed. This plastic rod can fall out when one removes the solenoid. If this rod is missing, the flash cannot pop-up anymore. Also a sign to watch out for when "not working" Pentax bodies are on sale such as this one (The Germany text says as well: Ex-repairshop cameras, I cannot tell if parts have been removed or not.... but he sells repaired K30's etc. with white solenoid):
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Forum: Pentax K-S1 & K-S2
05-25-2020, 02:15 AM
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Forum: Pentax K-S1 & K-S2
05-23-2020, 02:19 PM
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Forum: Pentax K-S1 & K-S2
05-08-2020, 07:30 AM
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Forum: Pentax K-S1 & K-S2
05-08-2020, 12:34 AM
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For now yes, but it won't last!
Don't wait too long but start to search for a Japanese solenoid and then DIY.
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Forum: Pentax K-S1 & K-S2
04-11-2020, 01:50 PM
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The magnetisation is lost pretty soon.
The solenoid acts as a push-pull device:
- The plunger pulls out and away from the permanent magnet when the two coils produce an opposite magnetic field (field-coil) and it acts to drive the diaphragm/aperture
- The plunger pushes back in and.... remains in this position near the permanent magnet!... when not used. So one could say that 99% of its live it is magnetised.
But the magnetism isn't a problem at all, the main factors/problems have been explained in detail.
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Forum: Pentax K-S1 & K-S2
04-10-2020, 09:55 PM
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There is no lubricant on the solenoid. Maybe somebody else lubed it before you bought it thinking lubing might help which is thinking in error.
But sanding the tips of the plunger is an error as well. I have explained this in detail.
The biggest problem can be misalignment of the complex mechanism which simultaniously controls mirror up and diaphragm control.
This photo shows a corroded plunger, it's surface has been sanded:
And this photo shows exodus after misalignment when one of the toothed wheels got blocked:
If the gearmechanism is misaligned one has to change the complete diaphragm-control-block and then align, it takes hour, did it once, never again:
https://www.pentaxforums.com/forums/members/85274-photogem/albums/13069-gear...ture125488.jpg |
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Forum: Pentax K-S1 & K-S2
01-23-2020, 05:30 AM
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The repairshops never use the white one because they can't get it new.
The green one possibly costs "them" 1-2 dollars so why should they:
- invest about 30 min. time to disassemble an old *ist/K100D/Kx etc including testing the solenoid?
- spend the money for an old DSLR body?
when they can have it the cheap way?
Some even modify the green solenoid!
This is photolab35 in California. He does the grinding/filing job and what comes out you can see here:
Solenoid problem return plus sound - Page 2 - PentaxForums.com
But it can happen worse, I have seen this to happen:
The white wheel got blocked because the filed/sanded plunger in this green China solenoid jammed and thus the spring "jumped out".
This then means a lot of work because one needs to exchange the complete diaphragm block:
Pentax 77860-G0100 Diaphragm Control Block | K-S2 | K-30 | K-50 | PartsUSCamera
Then a good solution is to swap the green China-solenoid on this block against the white Japan version
because often the green bugger sticks again.
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Forum: Pentax K-S1 & K-S2
12-11-2019, 01:47 AM
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Forum: Pentax K-S1 & K-S2
12-10-2019, 11:04 AM
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Bracketing is for sure a better solution than serial shots. Serial shots have led in the past to mal-alignement in the complex mechanism due to the solenoid being stuck but the rest trying to move (by force)
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Forum: Pentax K-S1 & K-S2
12-10-2019, 10:34 AM
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Optical preview can help because it does use the solenoid, but when it is really stuck opt. preview won't work anymore.
Best is ALWAYS to have the white Japan-solenoid ready and then find a good quite moment to do the work.
If you can move buttons, levers and knobs on a Pentax, you can repair it as well.
The biggest hinderance usually is our "head": It isn't set on Tv, Av, Tav, P, M but on A :fedup:or SCN:mad:-mode.
So one has to get away from A-Mode (= I can't do it:() but learn.
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Forum: Pentax K-S1 & K-S2
12-09-2019, 02:14 PM
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Well, you can check the manufacturing date and if it is a post-Dec.2015 model, it is much less likely to happen.
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Forum: Pentax K-S1 & K-S2
12-09-2019, 06:25 AM
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The white solenoid doesn't "seem to last", it lasts!
Huge difference.
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Forum: Pentax K-S1 & K-S2
08-13-2019, 11:50 PM
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Before my last message send a pm to member elpavorealduos and asked him if he was able to solve the problem. He answered:
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.
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Forum: Pentax K-S1 & K-S2
08-10-2019, 11:56 PM
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@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!
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Forum: Pentax K-S1 & K-S2
07-22-2019, 02:48 PM
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Forum: Pentax K-S1 & K-S2
06-16-2019, 09:41 AM
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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.
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!
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.
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Forum: Pentax K-S1 & K-S2
06-16-2019, 09:13 AM
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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.
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Forum: Pentax K-S1 & K-S2
06-13-2019, 12:54 AM
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At the beginning one didn't know it was the solenoid. When it became clearer (i.e. not yet really clear) it was adressed at the end of the K-50 in December 2015 as far as we have researched. The K-S1 was introduced Aug. 2014, the K-S2 Febr. 2015. So this is why we still find failures on early K-S1's and K-S2's.
The production of the (good never failing) pre-K30 Solenoid was in Japan but had been moved to China.
The China made solenoid was first "tried out" in the less critical flash-circuitry of the K100D, K200D and then K-m, K-x and K-r. Nothing went wrong, so it was finally installed into the aperture-mechanism of the K-30. It took a year or longer for the very first failures to happen, nobody took it that serious. First repairs where under warranty, so not yet public. This was later when the K-50 had replaced the K-30.
Then the problem became noticed, more regular but not yet as wide-spread as later on. Only since about a year or so the 2-nd hand offeres on platforms such as eBay and similar of aperture-failing K-30's and K-50's speak for themselves.
The culprit for sure is the solenoid (with very rare other exceptions... and even those exceptions often were a result of the failed China solenoid).
I will soon write more about what modifications were done (by Ricoh) to solve the problem of this solenoid up to now including the K-70.
The problem was that the Japanese manufacturer has moved production completly out of Japan, there are no more made in Japan solenoids available.
A common practice since decades.
The original Ashahi patent of using such a solenoid goes way back into analog days, the Pentax Program-A was one of the first (same design of the solenoid but 3Volts!) The MZ50, MZ6 and MZ7 used it: 6Volts but minor difference to the first DSLR bodies which have the best ones (for our use) starting with the ist*DS/DL, K100D, K200D, K10D and K20D up to K-m, K-x and K-r (but often China solenoid in the flash-circuit).
It was an amazing invention, it works very well. But now we have the problem that the Chinese have not yet delivered a solenoid of the same quality as the one made in Japan. The differences and why the China solenoid is inferior is known to many (and must be known to Ricoh!).
So to your other question:
I would only buy a K30/50/500 if either I am willing to repair it myself one day (because official repairs offered are based on modification of the green solenoid, i.e. filing it, which has resulted in failures again, or ... based on replacing the China solenoid with the same one again, not a great idea either, because even modified China solenoids are prone to failure, which I will explain later on)
There are less failures of the K-S1 and K-S2 or K-70. But a slight risk is there, I had 2 x bad K-S2 here and now, yesterday, the first K-S1 with solenoid failure.
7 reported K-70 failures on a German Pentax-forum. This is for sure way better because it was introduced 3 years ago, the failure rate is marginal compared to the K30/50's! With the K-S1 and K-S2 I would check manufacture dates and get a later model.
I still find the K30/50 with the 16MP Sony CMOS Sensor great bodies, a good photographer will be able to deliver almost as good photos with them as with the K70 but the K30/50 are more solid, rugged and I find it feels way better in my hands. Way better than the K-70.
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Forum: Pentax K-S1 & K-S2
03-11-2019, 07:03 AM
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I did understand it this way and totally agree. I think only AF-C can be critical for some, I never use it, so this would not bother me.
Then by all means... you have the advantage. It is straight forward, few hidden screws under the rubber, the K-S2 is the only Pentax body where you don't need to
take the screw out in the battery compartment, flash is a bit tricky to get to (for discharging it), it is on the other side, so battery out, let it stand for a week and don't
open the flash with the battery in.
Better not to go for the solenoid from the MZ50 or any other MZ, they are that tiny bit different, but any DSLR from K10D up to the K-r will do.
Don't take any solenoid from CD/DVD-Rom drives either, most have different impedance, some a different holding force, every solenoid was built to demand and specification. But all from the DLSRs I mentioned are guaranteed 100% identical and never failed.
I explained this HERE .
My experience with a lot of repaired (also sanded versions) K30/50/500/K-S1/K-S2's (I have repaired all of them) is exactly that:
DIY with the mentioned solenoid is the only 100% save long term solution.
Well, one shouldn't say 100% because any part can fail, even a white made in Japan solenoid. But they have never failed in any of the mentioned K-DSLR's nor was there ever reported a failure. When you have taken the green solenoid out of your K-S2 and then compare it just by pulling the plunger out of each several times...
I'd say everybody with some sensitivity will notice very clearly the difference.
So good luck! For you it should be peanuts.
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Forum: Pentax K-S1 & K-S2
03-11-2019, 03:58 AM
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You did. It was mentioned a few times.
DIY with a white solenoid is worth it particular for a camera with that low shuttercount.
That is true indeed. Because they cannot change the powersupply.
As much as sanded solenoid plungers failed, did repairs fail by authorized service centers.
Usually after 1 year.
The difference is that with the same solenoid built in the only danger is failure if the solenoid again.
Sanding the solenoid can lead to further damage because the plunger will move with more play and when pulled outwards the already slight angle of it is enhanced.
Only the plunger of the white solenoid sits straigth.It is a final solution.
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Forum: Pentax K-S1 & K-S2
03-10-2019, 12:26 PM
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That's how it is and with that low shuttercount a waste to use the sanding/filing method.
All has been explained, and yet... some love to go the cheap way.
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Forum: Pentax K-S1 & K-S2
02-04-2019, 08:08 AM
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yes! It is the green one.
This board was never built into any Pentax with a white solenoid!
The boards of the earlier Pentax cameras differs! Also not much, it does differ.
Anyway, it is so much more work to exchange this board, I myself would not be tempted to do it.
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Forum: Pentax K-S1 & K-S2
01-29-2019, 01:41 AM
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I don't think this has anything to do with Ricoh. Of course Ricoh would not sell used parts.
When I first saw their prices I just could tell, that their prices are much cheaper than what Ricoh asks for.
---------- Post added 01-29-19 at 01:41 AM ----------
No, they don't sell solenoids at all but the complete board, i.e the "aperture controll block" with the solenoid on it.
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Forum: Pentax K-S1 & K-S2
01-28-2019, 07:22 AM
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Follow up of my purchase of USCamera :
Few other people including me myself purchased several parts now for Pentax from USCamera:
Those are all used parts!
Amazing, but that's why there is only a 30 day return but no warranty!
But they don't tell you on their webside!
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