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03-19-2019, 11:23 AM - 1 Like   #31
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JerzyJ - No-one here will mind if you ignore the reasonable commentary and suggestions given above and sell your K-70 to buy a KP. However, it would seem likely that the 95% of satisfied K-70 users are not really interested in your rantings at Pentax for their failure rate, as it is not much different to that of other brands. And it is worth you considering that you might be someone unlucky enough to buy one of the 5% of KPs that might fail in the first few years of use.

Philip


Last edited by MrB1; 03-19-2019 at 01:01 PM. Reason: Sarcastic comment deleted.
03-19-2019, 11:53 AM   #32
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QuoteOriginally posted by stevebrot Quote
The number of reports of confirmed aperture control problems for the K-70 on this site is four (4) total since the camera's release, all of which in the last seven months. (..)
In the Pentax@PL link you shared, 21 respondents out of 68 total reported solenoid problems with the K-30, K-50, K-500, K-S1, K-S2, (K-70?). There was no breakdown by model except for member comments.
1. Yes, sorry, I checked it and couldnít edit my post... (is ot even possile) there was 8 similar problems with only 4 confirmed as aperture control issue. First three of them appeared within one or two months as figured in ĄreportĒ post.

2. Yes, the Polish survey was based on small group, but there is small group of pentax users in Poland in general. The survey took place during first few months after k70 release so there is small chance to register any problem with it.
Survey on this forum was sent to 5000 members but only 448 responded with 32% admitting to have aperture control issue. I know that this number may be far from real but basic survey methodology forbids to make assumption basing on non-respondents so itís definetely not 2% neither.

Please lets leave it here, delete my post if you need to. I dont want to fight with everybody and make mess on this forum. Time will show how the problem was managed by pentax, hope there will be no problems at all in the future.

---------- Post added 03-19-19 at 12:05 PM ----------

QuoteOriginally posted by MrB1 Quote
JerzyIn fact, perhaps the safest course of action would be to quit photography, other than to enjoy viewing the images taken by others who are happy to use their working Pentax, Canon, Nikon, etc. DSLRs until they also fail.

Philip
And please, at least try not to be rude when addresing to unknown person who is not rude to you, but just makes statement that you may not agree with.
Please leave it here, as I said: delete my post if forum hygene needs it and wait for any productive conversation instead.
03-19-2019, 12:06 PM - 3 Likes   #33
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QuoteOriginally posted by JerzyJ Quote
Does the change in selonoid mounting really fix problem occuring in earlier models? As I looked many users said that failure was due to cheaply made „green type” of selonoid- the same as seen in photos above... As for me it looks like Pentax ingeneers said „lets switch sides of this screw and tell people that we changed design of aperture block, no money invested in quality and they stop complain for a while”.
QuoteOriginally posted by photogem Quote
I don't think so.
When Ricoh noticed the problem the K-S1 and K-S2 where already out.
They could not change the design anymore, it would involve not necesserely a rise in voltage but a rise in milli-amperes (or both). This is why often (at least for a while)
the K30/50/500 would work with Eneloops, because they allow higher surge.


Sometimes people even noticed that the problem with the Li-Ion battery was stronger when it was fully charged.


I strongly believe the engineers found out too late, for a long time hoped it would not be that big and when it finally turned out that it was big, it was too late, the K-S1 and 2 were in the shops! I also believe that they then already did something, there was a massive "outlet sale" of K-S1's and K-S2's on the EU market (particular Germany), I believe they took new ones back into repair and modified something and sold them as ex-dem units!

Usually it is not engineers which make wrong decisions, its the econo-mist (mist in German = dung!)
But the engineers get slapped! They are forced to follow "those, who don't know a thing" but "pretend to know everything"

---------- Post added 03-19-19 at 01:43 AM ----------



Because repaired at Pentax.

With all K70's repaired and reported in Germany Ricoh wrote that it was the "Magnetschalter", which is the German translation for solenoid (magnetic switch)
QuoteOriginally posted by JerzyJ Quote
1. Yes, sorry, I checked it and couldn’t edit my post... (is ot even possile) there was 8 similar problems with only 4 confirmed as aperture control issue. First three of them appeared within one or two months as figured in „report” post.

2. Yes, the Polish survey was based on small group, but there is small group of pentax users in Poland in general. The survey took place during first few months after k70 release so there is small chance to register any problem with it.
Survey on this forum was sent to 5000 members but only 448 responded with 32% admitting to have aperture control issue. I know that this number may be far from real but basic survey methodology forbids to make assumption basing on non-respondents so it’s definetely not 2% neither.

Please lets leave it here, delete my post if you need to. I dont want to fight with everybody and make mess on this forum. Time will show how the problem was managed by pentax, hope there will be no problems at all in the future.
I see no need to delete your post - you have a valid opinion and concerns, and those concerns are understandable. But, since the level of aperture block failure on the K-70 seems very low at this stage, and none of us can see into the future, I'd respectfully suggest you're worrying prematurely. You're at just as much risk of buying a different model and having a completely different problem with that as you are of experiencing the aperture block issue with your K-70. In your situation, I would enjoy the camera and keep an occasional eye on the forums to see if the number of failures rises alarmingly... or simply deal with the problem if and when it occurs (most likely, it never will).
03-19-2019, 01:11 PM - 2 Likes   #34
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Apologies to JerzyJ - I have deleted my unnecessary remark. It was written in sheer irritation at the negativity arising from little evidence, which might put off other members from selecting a fine Pentax camera. In my view, we should remain positive about the K-70, unless the evidence becomes significantly clear to show otherwise..

Philip

03-19-2019, 04:34 PM - 1 Like   #35
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I wouldn't sell my K70 even if the danger of solenoid failure would be as risky as with the older K30/50's (which i don't think is the case!):
The repair is easy and straight forward, all that is needed is either a solenoid from an older DSLR Pentax (from *ist to K-x or K-r) or one buys it on ebay.com.

But no daubt, the KP is the better camera.
03-31-2019, 08:02 PM   #36
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Evidence of Aperture Block Failure K-70

QuoteOriginally posted by littlemoose Quote
Does anyone know if the k-70 has the same type of aperture/solenoid mechanism as the k-50, K-30 etc-prone to failure ?
QuoteOriginally posted by stevebrot Quote
The short answer is no one has done a published tear-down of a K-70, so the mechanism used is not known. The longer answer is that the diaphragm control block design in the failure prone models (K-30, K-50, K-500, and to a much lesser extent K-S2) has been used in almost all Pentax bodies dating back to the early 1980s with a high level of reliability. The problems that originally surfaced in the K-30 were apparently due to a change in quality in solenoid assemblies sourced from an outside vendor that carried over to two successor models (K-50 and K-500) in a fairly short product release cycle. All three models have essentially identical mechanical parts with the first K-30 failures became apparent during the time when most K-50s were produced and the cause was not characterized until after the release of the K-500.

There were reports of problems with aperture control on the K-S2, but it is unclear the degree of which those where traceable to failure of the diaphragm control block. It is possible that the K-70 has a control block similar to the K-S2, but not known for certain. In recent weeks, some users have expressed concern about the K-70. Reasons for this concern is not clear. In response to those concerns, a thread on this site has been dedicated to tracking all reports and characterizing the problem and cause where possible. For the current status:

K-70 Underexposed Photo Reports - PentaxForums.com

New reports are added as they are discovered, but are limited to experiences of registered users her at Pentax Forums.


Steve
QuoteOriginally posted by The Squirrel Mafia Quote
The few reports that are starting to come out seem to point to the K-70 having the same aperture motor issues as the K-30/50/500 & some K-S1/S2 cameras.

I wouldn't be surprised if Ricoh is still using the faulty "green" solenoid in them. I'd be willing to bet on that.

I had thought of buying one as a backup body for the future K-3II replacement, but I'm going to skip it. I already fixed my K-50 by replacing the "green" solenoid for a "white" one. Don't need to do that again.
QuoteOriginally posted by MrB1 Quote
Do you have evidence for this claim?

The PF Survey was sent to 5000 owners of the supposedly problem cameras. People are not usually reticent when it comes to reporting costly failures which are not of their own making, yet only 143 reported the Aperture Block Failure - that is 2.86%.

It is, of course, very disappointing that Pentax-Ricoh were so slow to respond after the reports of the K-30 faults - those were followed by similar proportions of faults in the K-50. However, they seem to have done something to improve the affected mechanism - there have been few reported cases for the K-S1/2 and hardly any for the nearly 3-year-old K-70. What there are lie well within the overall general digital camera failure statistics.

Philip
QuoteOriginally posted by JerzyJ Quote
We had similar survey on Polish forum which show ~23% of splenoid failures, 13% within first 10k shutter activations. I have to admit that methodology of this survey was different and no K70 user reported failure at the time.
PENTAX@PL :: Awaria w K-30 i dalszych

Again, I have to admit that each model has smaller group of aperture-related complaints, but 6-8reports within 3 months which can be found on this forum starts to built a concern.

And again I strongly hope that change in design was a fact and is just not visible, I donít think about changing systems in next 5 years at least as Pentax is real gamechanger in entry level market in aspect of picture quality and durability. The only thing I can consider is to sell my k70 untill it loses itís value and buy KP which seems to be more reliable and durable.
QuoteOriginally posted by stevebrot Quote
The number of reports of confirmed aperture control problems for the K-70 on this site is four (4) total since the camera's release (June 2016), all of which in the last seven months. Root cause remains unknown for all four. One of those four was reported from Poland by forum member @asalwa. That camera was repaired out-of-warranty by Pentax, though it is not known what service was performed.

In the Pentax@PL link you shared, 21 respondents out of 68 total reported solenoid problems with the K-30, K-50, K-500, K-S1, K-S2, (K-70?). There was no breakdown by model except for member comments. The last comment was posted Feb, 2019 with the survey started April, 2017. I read several of the comments and it appears that the discussion degenerated into a pattern familiar to users on this site. With any luck this thread will not follow a similar pattern.

Best wishes!



Steve
As has previously been reported I think I have just fallen victim to the "Aperture Block Problem" I am shooting K-70 and most recent shutter count is 4,144 images. I would like to get some feedback on this issue if possible, such as has Pentax stepped up to the "block" in regards to a fix for this issue, now spanning 4 or 5 models of cameras?

Please see images in my gallery re Aperture Failure.

03-31-2019, 08:19 PM   #37
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QuoteOriginally posted by SharkyCA Quote
I would like to get some feedback on this issue if possible, such as has Pentax stepped up to the "block" in regards to a fix for this issue, now spanning 4 or 5 models of cameras?
There is a thread on this site dedicated to the matter including how to confirm that your camera has an aperture control problem. You are welcome to participate posting as is appropriate there, particularly in regards to whether you are able to to confirm an aperture control problem as well as any repair center diagnoses and final outcomes. Example photos are not needed, since they are a symptom that contains few, if any clues.*

K-70 Underexposed Photo Reports - PentaxForums.com

If your camera is still under warranty or has come off of warranty within the last few months, I suggest you contact Pentax Canada to request warranty service.


Steve

* Strangely, a dark frame photo or even several is not evidence by itself of aperture controller block failure. There are multiple potential causes.

Last edited by stevebrot; 03-31-2019 at 08:35 PM.
03-31-2019, 08:33 PM   #38
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QuoteOriginally posted by stevebrot Quote
There is a thread on this site dedicated to the matter including how to confirm that your camera has an aperture control problem as well as of repair center diagnosis and final outcomes. You are welcome to participate posting as is appropriate there. Example photos are not needed, since they are a symptom that contains few, if any clues.

K-70 Underexposed Photo Reports - PentaxForums.com

Steve
Here are Steve's instructions for diagnosing the problem by actually observing the lens opening as you "take a photo"
QuoteOriginally posted by stevebrot Quote
The gold standard for diagnosing aperture block failure is to put the camera in M mode (auto ISO off, aperture ring not being used) with aperture set wide open and shutter speed at something slow (e.g. 1-2 seconds). Release the shutter while observing the aperture opening through the front of the lens.* Anything other than the aperture remaining wide open is indication of a problem with the controller. If the problem has been intermittent, it may help to do the test after a period of non-use. Even one failure is significant.

* This method was instrumental in diagnosing the initial wave of aperture block failures on the K-30 and narrowing the cause to a fault in a mechanical component rather than electronics.


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