[reh321]

I think the question from Pentax's standpoint is what percent of cameras failed in the warranty period. My guess is that the number was actually fairly small. Obviously this is a problematic way of looking at it, but on the other hand, the life span of these cameras isn't forever and Pentax has only guaranteed 1 year of warranty support in the US.

I guess the question, at this point, is whether current models -- K-P or K70 are affected by said issue. If they aren't then the last camera affected was the K50, which hasn't been current for three years. Certainly, even if this was an issue, Pentax isn't going to consider a current issue.

IIRC, at some show a Pentax representative confirmed that the KP does not use this aperture control design - presumably it use the design used in K-7/5/3.

[Hamiltom]

I think the question from Pentax's standpoint is what percent of cameras failed in the warranty period. My guess is that the number was actually fairly small. Obviously this is a problematic way of looking at it, but on the other hand, the life span of these cameras isn't forever and Pentax has only guaranteed 1 year of warranty support in the US.

I guess the question, at this point, is whether current models -- K-P or K70 are affected by said issue. If they aren't then the last camera affected was the K50, which hasn't been current for three years. Certainly, even if this was an issue, Pentax isn't going to consider a current issue.

There are reports of failures in the K-S1 and K-S2 bodies as well, which were introduced well after the K50.

[Rondec]

There are reports of failures in the K-S1 and K-S2 bodies as well, which were introduced well after the K50.

I had a K-S1 failure, so no argument from me, but these still aren't current cameras.

I'm not saying that Pentax shouldn't have fixed these cameras, I'm just saying it isn't surprising that they feel that the rate of failure wasn't unusual as most of the cameras made it past the year mark before exhibiting problems.

[clackers]

This Forum did a poll of its K-30 and K-50 owners, and five hundred (including me) responded. As someone noted:

"As you mention the survey bias means that the failures rates reported here are necessarily higher than the actual rates, but are good to observe as the upper bound. Estimating the lower bound is easy as well. As most respondents will be those with an axe to grind (ie failure = true), you can approximate that non respondents are those that did not have camera failures. So for the K30 and K50, respectively, the estimated minimum failure rates are 165/2659*100 and 107/1799*100. Both work out to ~6%."

[reh321]

The topic of this thread is "is aperture block really a problem?". I had two Canon Rebels die of processor failure. I would not be surprised if processor failure is the primary cause of Rebel death, while aperture control failure is the primary issue with comparable Pentax cameras. I trashed my Rebels, while my K-30 would be usable to me with the manual lenses I have accumulated.

[reh321]

I'm not saying that Pentax shouldn't have fixed these cameras, I'm just saying it isn't surprising that they feel that the rate of failure wasn't unusual as most of the cameras made it past the year mark before exhibiting problems.

At my rate of under 1000 shutter actuations per year, I expect a lot more than a year from a camera, even a camera at that tier. Beginning 1969, I have had nine cameras; I list two as "failures" - a Canon compact that I gave up on after 9 months because it didn't meet my needs, and a Canon Rebel that lasted 1-1/2 years, 800 shutter actuations, before dying with processor failure. Even with its incipient Dark Image Syndrome, my K-30 has now reached 41 months, and is officially a "success".

However, it bothers me when people will say things such as "there is really no difference other than price between a K-70 and a KP"; if we say that we cannot expect more than a year or two from a camera at the K-70 level, then we need to acknowledge that as a real difference, because the KP is clearly much closer to the K-3ii in build quality and expected service life.

[runswithsizzers]

What constitutes "acknowledgement"? My memory is that they became aware of the problem about the same time as the rest of us, that Pentax customer service and repair facilities were helpful, that repairs were made under warranty and that Ricoh extended warranty by several months for several users on this forum based in part on the frequency of the issue. Unfortunately, the problem typically began to manifest post warranty and in the case of some users whose cameras were used sporadically, several years passed before they noticed there was a problem.

[...]

The accusation is often made that Ricoh continued to produce cameras with known-bad components for years after the issue became apparent. The assumptions being:

• That they were aware of the extent of the problem with the K-30 before the bulk of K-50 bodies were made
• That the problem had been fully characterized soon enough to avoid using the culprit solenoids
• That the culprit solenoids could be demonstrated defective at some point in the QA process
• That Ricoh put full production runs to market knowing there was a fatal flaw that would only manifest after warranty expiration

Whether any of the above are true is difficult to establish.

Steve

(...had failure of a K-50 purchased for a close friend that happened two months out of warranty in Winter 2015...fixed at no charge by Pentax...)

I am not "accusing" Pentax of anything except possibly lack of communication. If it is difficult to establish the facts of what happened when, it is because Pentax hasn't said.

An "acknowledgement" would appear on the Pentax website or in an industry newsletter. The source would clearly be identified as originating from Ricoh or Pentax. The wording would convey the following message:

Ricoh/Pentax has discovered a part in our supply chain which sometimes does not perform as expected. If owners of Pentax K-30, K-50 (etc.) experience the following symptoms [described here] contact a Pentax repair center and we will work with you to resolve the problem. [contact info here]

We have found an alternate source for the questionable part, and cameras manufactured after dd/mm/yy should not be affected.

If there is/was a publiclly available statement from Pentax to that effect, then I stand corrected.

[kernos]

Hope indeed that the KP has the K3/5/7 acb. I've had a k30 and k50 acb failure while my well used, purhased used K5iis soldiers on. Agree with whoever said to stick with flagship models. Had I started with a K5 in the beginning it would have saved some money for sure. Really the issue now is whether Pentax can be trusted to improve engineering and reliability with subsequent models or just add more semi useful features for a higher price. This seems to be how the acb issue propagated. But I'm just a simple fellow who uses a handful of controls for all my photos.

[stevebrot]

I would not be surprised if processor failure is the primary cause of Rebel death, while aperture control failure is the primary issue with comparable Pentax cameras.

I would suggest that conclusion regarding Pentax might be wrong. The most common causes in my ten+ years on this site are water incursion, physical damage, and processor failure.

At my rate of under 1000 shutter actuations per year, I expect a lot more than a year from a camera, even a camera at that tier.

I get your drift and tend to agree*, though some might ask if the failure had been something other than aperture control block ("Dark Image Syndrome") whether one would be as vocal about the issue. You list two Canon Rebels as dying prematurely. If one puts any faith in the surveys at Consumer Reports, one out of 13 people receiving a box marked Nikon (all models) on the same day as your purchase had a similar short service life (three years or less). I don't consider any of those numbers acceptable despite all being better than for laptop computers and on par with other consumer electronics.


Steve

* I would have bought a Sahara version K-50 from Costco had they not run out of cameras.

[stevebrot]

An "acknowledgement" would appear on the Pentax website or in an industry newsletter. The source would clearly be identified as originating from Ricoh or Pentax. The wording would convey the following message:

Ricoh/Pentax has discovered a part in our supply chain which sometimes does not perform as expected. If owners of Pentax K-30, K-50 (etc.) experience the following symptoms [described here] contact a Pentax repair center and we will work with you to resolve the problem. [contact info here]

We have found an alternate source for the questionable part, and cameras manufactured after dd/mm/yy should not be affected.

That would have been wonderful.


Steve

[stevebrot]

Really the issue now is whether Pentax can be trusted to improve engineering and reliability with subsequent models or just add more semi useful features for a higher price. This seems to be how the acb issue propagated.

As noted multiple times in the last few months, the design has been well-proven and highly reliable in over 35 years of service in the majority of Pentax SLR cameras produced since the early 1980s. The point of contention is whether the deficiency in question was approachable through available QA methods either then or now. The same is true regarding forensic evaluation of affected bodies. The threads on this site detailing owner theories and purported fixes are a good example of how hard it is to do fault isolation for this sort of issue.

In my analysis and personal opinion, the ACB issue did not propagate as much as it was not adequately characterized until late in the production cycle of a particular platform (K-30/K-50/K-500). It should be noted that the actual behavior* is still not testable in new bodies or new solenoids from the supplier.


Steve

* The difficulty of the ACB failure was that it was not wear or duty cycle related with the conditions to reproduce being unclear to this day.

[reh321]

As noted multiple times in the last few months, the design has been well-proven and highly reliable in over 35 years of service in the majority of Pentax SLR cameras produced since the early 1980s. The point of contention is whether the deficiency in question was approachable through available QA methods either then or now. The same is true regarding forensic evaluation of affected bodies. The threads on this site detailing owner theories and purported fixes are a good example of how hard it is to do fault isolation for this sort of issue.

In my analysis and personal opinion, the ACB issue did not propagate as much as it was not adequately characterized until late in the production cycle of a particular platform (K-30/K-50/K-500). It should be noted that the actual behavior* is still not testable in new bodies or new solenoids from the supplier.

Apparently a component supplier changed the materials being used, and the new formulation didn't age as well as the original did. Both my Super Program and my K-30 contained the solenoid in question. I used my Super Program steadily 1983-95, and occasionally ever since, and the aperture control still works. I have used my K-30 steadily 2015-today, and the aperture control started failing this past summer. Experience of other people is the same as mine.

[stevebrot]

But the actuations of the K10/20/100/200D's speak for themselves. This is prove, fact, if you like it or not!

The good folk at PC35 PhotoLab (pentaxcamerarepair.com) claim multiple affected models including several that presumably have the white-clad solenoid though at lower frequency of requested repair.

This repair service applies to the repair of aperture control block failure in several Pentax DSLR models including the K-30, K-50, K-S2, K-r, K-x, K100D, and most older istD models. This list may not be complete. Aperture control block failure is most common in the K-30 and K-50. It is less common in other Pentax models.

Yes, K100D is on the list...

I made this comment to qualify the nature of "fact" being somewhat dependent on the observer and their purpose. A demonstrable fact is that any part may fail on any model. I might also comment that the matter of country of origin for installed solenoids is without firm evidence, though the correlation of color is quite convenient. Whether it was Pentax or their supplier that made the change is also a little "soft". I could go on. This is not to say that your research is flawed, only that the conclusions are not as obvious as I might accept.

Your contributions here in regards to characterizing this issue are indisputable and worthy of respect. I fielded the original help requests on this site from K-30 users who suffered failure of aperture control and/or mirror control (the two are related) and later those from the K-50. The initial flurry was truly alarming and there is no question that the issue was common, if not pervasive. Whether some production runs were more prone and whether those runs were more commonly represented in some markets (e.g. Europe) is possible, but also hard to firmly assert. What is known is that users on the European and Russian discussion groups were much more aggressive in exploring DIY repair options than on this forum and I acknowledge their contributions as well.

Moving on, aperture block failure with the most commonly affected models (K-30/K-50/K-500) is fast becoming ancient history in that the number of cameras likely to experience first-time failure is trailing off.

Note: I see that your account status changed while I was typing this comment. That is regrettable in so many ways, though I can understand the rational.


Steve

[normhead]

I gotta ask, how is this possible?

My K-30, which I've had for 2-plus years, is at 260,000 shutter clicks and climbing....

?

[reh321]

My K-30, which I've had for 2-plus years, is at 260,000 shutter clicks and climbing....

I gotta ask, how is this possible?

The evidence is that the aperture control is the the weak link on the K-30/50 .... the shutter is at least as good as any other consumer-grade shutter .... and the aperture control 'likes to work'; often we will see a post that says something like "I took my K-30 off the shelf where it had sat for a month, and suddenly the images were dark" - obviously a camera which is churning out 100K+ images per year isn't experiencing much 'idle time'.