[Bertrand3000]

The K-S2 manufactured before december 2015 are more likely to suffer from aperture block failure than the ones manufactured later. New models still use green solenoids, so I suppose that the new green solenoids are much more reliable than the older green solenoids (but white solenoids are still much better, period). So a repair is likely to use a new green solenoid, and will probably last.


It cannot be compared, I think, to the SDM fiasco, where lenses with SDM failure, officially repaired, still fail on a regular basis.

[Dan]

Dan, I'm very loyal to the brand. I love my Pentax gear.
Go right ahead and use the green solenoid repair. Just don't say I gave you that advice.

Mark, If you are loyal to the brand then I kindly suggest that you avoid spreading baseless rumors about failure rates of Pentax gear. Your statement that the green solenoid is likely to fail implies that people who buy a K-70 should expect it to fail. That's nonsense. When such exaggerations come from a forum moderator they are more likely to harm the brand than when they come from known brand bashers.

You say "go right ahead and use a green solenoid repair", which suggests that I have proposed this. To the contrary, I wrote that "clearly it is better to do the repair with the white solenoid", because it has a lower failure rate than the green solenoid. I did not take issue with your advice that the white solenoid is the preferred solution. I only took issue with your baseless statement that the green solenoid is likely to fail. It is possible to provide good repair advice without overstating the statistical basis for that recommendation.

I have both a K-S2 (from the early, less-reliable production run) and a K-70. Both have performed flawlessly. Neither is "likely" to fail. People who are considering a purchase of the K-70 should not be dissuaded by folks who draw faulty statistical inferences from anecdotal data.

Dan

[que es tu]

I would think a kp will be found for cheap soon with the up coming apsc camera due fairly soon. In the mean time i would look for deals on a couple old manual primes or the 55-300 plm so your ks-2 can go on in full block failure.

Yes, this is another idea! I have some time for the price to come down as I only get 1 dark frame after powering up the camera, but I suspect it will get worse. Maybe it will hold off until I can afford a KP or a PLM lens!?

---------- Post added 06-18-20 at 09:28 AM ----------

The K-S2 manufactured before december 2015 are more likely to suffer from aperture block failure than the ones manufactured later. New models still use green solenoids, so I suppose that the new green solenoids are much more reliable than the older green solenoids (but white solenoids are still much better, period). So a repair is likely to use a new green solenoid, and will probably last.


It cannot be compared, I think, to the SDM fiasco, where lenses with SDM failure, officially repaired, still fail on a regular basis.

My KS-2 was made 4-23-15

---------- Post added 06-18-20 at 09:30 AM ----------

Yeah, look, the white solenoids are no longer made by the supplying company. That company relocated production to China, the new ones are green, and obviously don't have the same quality control. The solenoid company probably offers a twelve month warranty, and Pentax would use that within their own twelve month warranty.

My K-S2 is perfectly fine after all these years, but if I was in your situation I'd really think about saving up for that KP. It does not use a solenoid to control aperture, it has a more expensive stepper motor like in the Pentax flagship models.

It seems as though the solenoid design is inherently flawed. If the KP is more reliable that may be the way to go.

---------- Post added 06-18-20 at 09:39 AM ----------

By one survey done here, it's possible to make assumptions and interpolate the failure rate to be as low as maybe six percent. You'd have to be unlucky to happen to you twice, if the probabilities are independent (admittedly, not likely, tolerances of other parts such as the plunger mechanism itself must enter into it) - six percent of six percent.

For years I have had both a K-30 and a K-S2 that have not had a hint of trouble, but on the other hand, who wants to be unlucky?

Yeah, once bitten, twice shy!! I've been unlucky once, and I don't like it!

[automorphism]

By one survey done here, it's possible to make assumptions and interpolate the failure rate to be as low as maybe six percent. You'd have to be unlucky to happen to you twice, if the probabilities are independent (admittedly, not likely, tolerances of other parts such as the plunger mechanism itself must enter into it) - six percent of six percent.

Just a note on the mathematical reasoning here: the probability of a second solenoid failing on the OP is still six percent (or whatever the failure rate is). 0.06*0.06 = 0.0036 is the probability of having two failures given that you haven't had any failures yet.

Since the OP already knows the information that one failed, and assuming independence like you said, the probability that his second solenoid will fail is still p=0.06. That is what independence implies. In other words, the OP should not feel like it is more unlikely than average for the second green one to fail given that the first one already failed, since the first one failing has no influence on the second one failing, again assuming independence.

[Apet-Sure]

Greetings from the Eastern side of NC and welcome to the forum. Here is a side-by-side comparison of the K-S2 and KP in case you haven't already seen this.
Pentax K-S2 vs. Pentax KP - Pentax Camera Comparison - PentaxForums.com

According to this comparison, both cameras use the same battery, so battery life shouldn't be much of an issue. The KP's built-in flash is quite weak, with a GN of 6 at ISO100 compared to the K-S2's GN12. Presumably this was done to extend battery life and because the KP is so good at high ISO settings.

I bought my KP used from a PF member at a very significant discount, and have really been enjoying it. Believe me, I understand tight budgets. But if there is any way you could scrape together the funds for a KP, that would be my recommendation. It's a wonderful camera overall. If you ever get over this way (an hour Southeast of Raleigh) you are welcome to take mine for a test drive.

[que es tu]

Greetings from the Eastern side of NC and welcome to the forum. Here is a side-by-side comparison of the K-S2 and KP in case you haven't already seen this.
Pentax K-S2 vs. Pentax KP - Pentax Camera Comparison - PentaxForums.com

According to this comparison, both cameras use the same battery, so battery life shouldn't be much of an issue. The KP's built-in flash is quite weak, with a GN of 6 at ISO100 compared to the K-S2's GN12. Presumably this was done to extend battery life and because the KP is so good at high ISO settings.

I bought my KP used from a PF member at a very significant discount, and have really been enjoying it. Believe me, I understand tight budgets. But if there is any way you could scrape together the funds for a KP, that would be my recommendation. It's a wonderful camera overall. If you ever get over this way (an hour Southeast of Raleigh) you are welcome to take mine for a test drive.

Hello from the high country!! I have 2 batteries for the KS-2 so that should be plenty. Also , I will probably get a hot-shoe flash anyway. Coincidentally, I have been looking at the KP for a while, but I had hoped my KS-2 would have lasted another 3 years so I could use my 25 yr bonus at work for an upgrade! If I get a KP now, then I con use the bonus for a couple of Limiteds!! YUMMY!!

[Just1MoreDave]

Your broken KS-2 should sell for something. I occasionally look for one. If I wasn't going on a trip tomorrow I'd make you an offer. Maybe in ten days or so.

[MarkJerling]

Mark, If you are loyal to the brand then I kindly suggest that you avoid spreading baseless rumors about failure rates of Pentax gear.

The higher failure rate of Pentax camera models with a green solenoid is well documented in this forum and, indeed, all over the internet. It's not a "baseless rumour".

Your statement that the green solenoid is likely to fail implies that people who buy a K-70 should expect it to fail. That's nonsense.

There is some evidence that the aperture control mechanism in the K-70 has been redesigned so as to ensure that the green solenoid works better than in in earlier models such as the K-30 and the K-50. My opinion is that I would not trust a green solenoid replacement but, if the repair involves replacing the entire aperture control mechanism then I see no problem. Apologies if I have not made that clear.

When such exaggerations come from a forum moderator they are more likely to harm the brand than when they come from known brand bashers.

Based upon the evidence on this forum and others, I don't believe I'm overstating the green solenoid issue. That is my point of view, as a member. At the same time, I've been exclusively using Pentax cameras since the 1980s and I encourage every one I come across to purchase Pentax gear. I'm somewhat flabbergasted that you choose to align me with brand bashers. The fact that your green solenoid equipped camera is functioning correctly is great. That should not prevent any member from looking to provide advice that (I believe) is likely to ensure trouble free operation for many years to come.

To the contrary, I wrote that "clearly it is better to do the repair with the white solenoid", because it has a lower failure rate than the green solenoid.

We appear to be singing from the same song sheet.

I only took issue with your baseless statement that the green solenoid is likely to fail. It is possible to provide good repair advice without overstating the statistical basis for that recommendation.

You have a problem with my use of the word "likely" I apologise for the use of the word "likely" Would you be happy if I said "more likely"?

I have both a K-S2 (from the early, less-reliable production run) and a K-70. Both have performed flawlessly. Neither is "likely" to fail. People who are considering a purchase of the K-70 should not be dissuaded by folks who draw faulty statistical inferences from anecdotal data.
Dan

As noted, the K-70 is, based upon reports from members, less likely to exhibit the problem, possibly as some members have pointed out, due to a change in design of the whole aperture mechanism. The green solenoid has, after all, worked well in other applications, such as for pop-up flash operation, so it can be that the change of design of the aperture mechanism in the K-70 has solved the issue. But, it's also a bit early to say for sure, as the problem tended to show up only after some use in K-30 and K-50 cameras, so it could be argued that time will tell with K-70 cameras. For the money, if it was me, I'd rather buy a KP to avoid the (to me) risk. When I buy any gear, I expect it to work for many years as I can't afford to upgrade my gear regularly. I imagine Ricoh has been as annoyed about this issue as users have been. And, if other members are correct, then they have been working to fix the issue.

Your statistical position is no different from mine. You have two cameras that work well. That's as anecdotal as my comments, except that I base mine on reading about the issue for some years. I just wish the designers of these cameras used the same system as in my K5 and K-1 because, (to me) that would seem to indicate to be the better system. I know of no aperture control issues with K7, K5, K5ii, K3, K3ii, K-1, K-1ii or KP cameras so, anecdotally, it would seem that system is the better design.

I trust that clarifies my position.

[marcusBMG]

My KS2 is showing signs of aperture soleoid failure too. However everytime so far I have easily been able to clear it by firing off a few frames. In fact I noticed a post suggesting assigning the raw/fx button to stop down preview. I did this, and now if I get a dark frame I just press that button a few times and then no problem... so far.
I actually acquired a for parts K100D to do the repair - I already did a K30, it's not a difficult diy, you do need a soldering iron with a fine point tip. If you've ever done any small component electrical soldering it's trivial.
KS2 is a nice camera, in some ways I prefer it to the K3. I have already had a few instances where the fully articulated lcd has been a boon.

[que es tu]

My KS2 is showing signs of aperture soleoid failure too. However everytime so far I have easily been able to clear it by firing off a few frames. In fact I noticed a post suggesting assigning the raw/fx button to stop down preview. I did this, and now if I get a dark frame I just press that button a few times and then no problem... so far.
I actually acquired a for parts K100D to do the repair - I already did a K30, it's not a difficult diy, you do need a soldering iron with a fine point tip. If you've ever done any small component electrical soldering it's trivial.
KS2 is a nice camera, in some ways I prefer it to the K3. I have already had a few instances where the fully articulated lcd has been a boon.

Yeah, I've been using DOF preview to get the aperture to work, too. I just don't know how long it will last. Also, I have been using drive mode to clear it out too, with the result that I had about 70-80% unwanted photos on a week- long backpacking trip!

[Dan]

The higher failure rate of Pentax camera models with a green solenoid is well documented in this forum and, indeed, all over the internet. It's not a "baseless rumour".

Correct, a higher failure rate among cameras with the green solenoid is not a baseless rumor. But that is not what you said. You said that a repair using the green solenoid is likely to fail. It is that statement which is baseless.

Based upon the evidence on this forum and others, I don't believe I'm overstating the green solenoid issue. ...

Are you referring to your revised statement (that they have a higher failure rate than the alternative) or your original statement (that most of the solenoids fail)? The evidence published on this forum suggests that your revised statement is correct, but that your original statement is an exaggeration.

You have a problem with my use of the word "likely". I apologise for the use of the word "likely" Would you be happy if I said "more likely"?

Yes, thank you! We agree that a repair with the green solenoid is more likely to fail than a repair with the white solenoid. We also agree that cameras that use the green solenoid are more likely to fail than cameras--such as the K-P--that use an alternative mechanism. As I have said repeatedly, my objection was to your claim that a repair with the green solenoid is likely to fail.

As noted, the K-70 is, based upon reports from members, less likely to exhibit the problem, possibly as some members have pointed out, due to a change in design of the whole aperture mechanism. The green solenoid has, after all, worked well in other applications, such as for pop-up flash operation, so it can be that the change of design of the aperture mechanism in the K-70 has solved the issue. But, it's also a bit early to say for sure, as the problem tended to show up only after some use in K-30 and K-50 cameras, so it could be argued that time will tell with K-70 cameras.

The K-70 was first sold in September 2016, which is almost 4 years ago. The survey results for the K-30 published on this forum suggest that there is a large spike in solenoid problems after the first year, and that the failure rate goes down after year three, so I believe you are wrong when you say that it's "a bit early to say".

Your statistical position is no different from mine. You have two cameras that work well. That's as anecdotal as my comments, except that I base mine on reading about the issue for some years. I just wish the designers of these cameras used the same system as in my K5 and K-1 because, (to me) that would seem to indicate to be the better system. I know of no aperture control issues with K7, K5, K5ii, K3, K3ii, K-1, K-1ii or KP cameras so, anecdotally, it would seem that system is the better design.

I am basing my conclusions on survey evidence, as well as reading countless forum posts through the years, both here and abroad. I have followed this issue quite closely. The alternative aperture control system used in higher-end cameras is clearly more reliable. Having said that, the problem with green solenoid can be overstated.

Dan

[gatorguy]

The higher failure rate of Pentax camera models with a green solenoid is well documented in this forum and, indeed, all over the internet. It's not a "baseless rumour".

Your statistical position is no different from mine. You have two cameras that work well. That's as anecdotal as my comments, except that I base mine on reading about the issue for some years. I just wish the designers of these cameras used the same system as in my K5 and K-1 because, (to me) that would seem to indicate to be the better system. I know of no aperture control issues with K7, K5, K5ii, K3, K3ii, K-1, K-1ii or KP cameras so, anecdotally, it would seem that system is the better design.

I trust that clarifies my position.

Another anecdotal comment:
I've owned (or own) three KS2's and two K-70's. No failure's here.

[Marktax]

I've had a KS-2 since 2016 and have less than 14,000 clicks on the shutter. However, I have begun to get DARK FRAMES!! Should I repair it, or get a used KP?? I really like the S-2, and hoped it would last a few more years as I really won't have the money for a KP until next year at the earliest. If it seems logical I would rather pay the 200+ to repair. Any word on repair longevity?? Thank you!

I repaired mine myself several thousand frames ago, using the aperture block "filing" method. I think one simply needs to know how to file the part correctly. I will certainly report if mine ever fails again.

[clackers]

Just a note on the mathematical reasoning here: the probability of a second solenoid failing on the OP is still six percent (or whatever the failure rate is). 0.06*0.06 = 0.0036 is the probability of having two failures given that you haven't had any failures yet.

Well, that's what I said. The probability of it happening twice.

And I even discussed independence of events with the OP, I'm sure he gets it, let's not underrate him.

[que es tu]

Well, that's what I said. The probability of it happening twice.

And I even discussed independence of events with the OP, I'm sure he gets it, let's not underrate him.

You know, 6% doesn't sound like a very big number, until you are in that 6%. Then it gets to be a REALLY big number!!