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08-07-2020, 08:56 PM - 5 Likes   #1
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K-70, aperture block solenoid, extended warranty, and Precision Camera

A positive experience getting the aperture block solenoid repaired on my K-70, using the Pentax 3-year extended warranty and Precision Camera (the Pentax authorized service center for the USA).

My K-70 started to develop the aperture solenoid failure. Just an occasional dark first frame, followed by several correct exposures, but I knew from my K-50 that this would get worse. I contacted Ricoh US with some questions on what I need to send in with the camera (I had purchased the 3-year Pentax warranty for $17 when I bought the camera in late 2017 so it was still under this warranty). Precision Camera called me a week later, and said I didn't need to send any evidence of the failure, just send the camera alone after filling out the repair form on the website, along with copies of the original purchase receipt and a copy of the extended warranty card. I sent it on July 12th, they received it on July 15th, and I had it back in my hands by July 23rd. The "Explanation of Repairs" stated: "Aperture Replaced. A complete repair and return of all functions to factory specs. Current FW Ver 1.11. Complete cleaning." I had verified with them on the phone that they would clean the sensor as well (it had some dust). Under "Description of Parts Used" they stated "Aperture control Assy., resistor chip." Total price: $0.00.

So, I'm quite happy with Precision Camera and the whole process. And I'm very glad I decided to spend that extra $17 on the extended warranty. Now I just have to figure out all the custom settings I had in the camera, and check to see if I need to re-enter those.

I thank all the members of the Pentax Forums for sharing helpful information about the nature of this solenoid problem, their experiences with their cameras and with repair options. It has been very helpful.

Thanks - Richard.

08-08-2020, 04:52 AM   #2
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Interesting as in the earlier models Precision would replace the Diaphragm Control Block - assembly of gears and the suspect solenoid. In this case Precision sounds like they replaced part of the circuitry.
08-08-2020, 08:38 AM   #3
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QuoteOriginally posted by Not a Number Quote
Interesting as in the earlier models Precision would replace the Diaphragm Control Block - assembly of gears and the suspect solenoid. In this case Precision sounds like they replaced part of the circuitry.
Perhaps the "aperture control assembly" is the same as the "diaphragm control block"? Not sure. I wonder if a parts diagram of the K70 is available?
08-08-2020, 08:47 AM   #4
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QuoteOriginally posted by OldChE Quote
Perhaps the "aperture control assembly" is the same as the "diaphragm control block"? Not sure. I wonder if a parts diagram of the K70 is available?
That's probably so but they never listed the "resister chip" before.

08-08-2020, 09:17 AM   #5
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QuoteOriginally posted by Not a Number Quote
That's probably so but they never listed the "resister chip" before.
It had been listed on some repairs in Europe,* but this is the first I have heard of it here. At that time, the existence of the "resister chip" was disputed by some.


Steve

* Back when I was doing the reportage thread for aperture block failure on the K-70.
08-12-2020, 12:42 AM   #6
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That was me disputing the existance of such a resistor chip because there is none.

It wasn't listed by "some repairs" in Europe but one (Ljubljana).


I think they try to make it special by inventing something that is not there.

So people might get worried if they just replace the solenoid by themselves there could still be another part wrong.
Same nonsense as inventing problems of brushes or bushes deeper inside the diaphragm-mechanism which need to be cleaned and lubed.

Behind the diaphr. contr.unit which works with a solenoid on many but with a stepper-motor on K7/5/3/1/KP and K-01 there is a similar mechanism
with contacts. So if this invention would be true, those bodies should fail as much as those with a solenoid. Which is not the case.
08-13-2020, 04:50 PM - 1 Like   #7
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It's great that Precision fixed this for you but it's very disappointing that this fault now seems to be appearing in a third (?) generation of Pentax camera's, especially as it seems that all that would be needed to fix the problem would be to use a different part in the manufacturing process. I mean how much would a different solenoid cost - a few dollars per unit?? Frankly, it's really not good enough from Ricoh.

08-14-2020, 02:38 AM   #8
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QuoteOriginally posted by OldChE Quote
Now I just have to figure out all the custom settings I had in the camera, and check to see if I need to re-enter those.


Thanks - Richard.
Regarding this, just wondering, is there a option to save the content of the custom setting to the SD card? On any K-DSLR? Would be a handy option...
08-14-2020, 08:29 PM   #9
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QuoteOriginally posted by yucafrita Quote
Regarding this, just wondering, is there a option to save the content of the custom setting to the SD card? On any K-DSLR? Would be a handy option...
Don't know. That would be nice.
08-26-2020, 03:44 PM   #10
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QuoteOriginally posted by carlb Quote
It's great that Precision fixed this for you but it's very disappointing that this fault now seems to be appearing in a third (?) generation of Pentax camera's, especially as it seems that all that would be needed to fix the problem would be to use a different part in the manufacturing process. I mean how much would a different solenoid cost - a few dollars per unit?? Frankly, it's really not good enough from Ricoh.
My thoughts exactly.
I bought my daughter a new k50 now the apertures failed ...
I was looking at K-70 as a replacement

I was disappointed to tell her maybe she should dump Pentax and go mirrorless
08-27-2020, 01:14 AM - 1 Like   #11
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QuoteOriginally posted by OldChE Quote
........ Precision Camera called me a week later, and said I didn't need to send any evidence of the failure, just send the camera alone .....
Because of course they knew what the problem was!
QuoteOriginally posted by OldChE Quote
......after filling out the repair form on the website, along with copies of the original purchase receipt and a copy of the extended warranty card. I sent it on July 12th, they received it on July 15th, and I had it back in my hands by July 23rd.
Luckily you had this extended warranty!
QuoteOriginally posted by OldChE Quote
The "Explanation of Repairs" stated: "Aperture Replaced. A complete repair and return of all functions to factory specs. Current FW Ver 1.11. Complete cleaning." I had verified with them on the phone that they would clean the sensor as well (it had some dust). Under "Description of Parts Used" they stated "Aperture control Assy., resistor chip."
In a way this "Explanation of Repairs" stating: "Aperture Replaced" is.... with all due respect.... sheer nonsense!
Maybe just some typo by an unexperienced person
but really:


The aperture (diaphragm) is in the lens! For sure no aperture was replaced!

Inside your Pentax is a "aperture-control-unit", also called "diaphragm-control-block"
To control/operate the aperture/diaphragm!

What they got right is "Firmware Update" and "Cleaning".



But then we have something which just is an invention: This mysterious 'resistor chip'

The circuit has been the same since even SLR days, just voltage changed a bit since DSLR days and the original Pentax *istD.

The solenoid is driven by a so-called solenoid-driver, sitting on the upper flexboard (T700).

This solenoid-driver is at the same time the powersupply (but more complex) and if damaged, the solenoid can not fire anymore.

The solenoid-driver is soldered with 48 tiny contacts onto the upper flexboard, unsoldering almost impossible, one just replaces the whole flexboard!

But this was hardly ever needed because luckily it very rarely got damaged!

It can get damaged though if one files/sands the plunger!


What ALWAYS happened was that the plunger of the solenoid got stuck due to magnetisation!

When the camera is not in use i.e. does not fire, the solenoid is in "pull" action, i.e.the plunger is pulled towards the permanent magnet and stays there.
And thus together with other factors (friction in the housing which acts as a bearing) it can jam, i.e. the counteraction of the 2 electromagnetic coils is not enough to release the plunger. That's all, Anything else is fabrication, invention, fairy-tales!

A different solenoid-driver could in a way work but would just be compensation (to ease a problem).
Nobody would do that, it would be idiotic!


What Ricoh did was modify the solenoid since late K-S2 production days and since then we had very few failures, the same applies to the K70.

Because this "dark-image-syndrome" (solenoid failure) has become something quite large (and now is way out of proportion) any failure gives rise to something like "they did it again"... "they could not solve it" etc. Which is not true but thats how human psychologie functions... it's called pattern or classical conditioning (Pavlovian behaviour)


I guess that those who repair now those rare failures chose to name the repair differently. I can understand this because it is an attempt to deflect something that blew out of proportion but to name it "Replacement of aperture" or "repair resistor-chip" is not very intelligent either!


But actually here in this forum we have a very different problem:

Some (without any technical background) try to deflect as well. Some just try to deflect from the solenoid and others try to invent fairy-tales.

Doing this they actually just cause more damage (to Ricoh/Pentax) because it is an odd kind of bending over backwards of real facts and thus trying to dilute.
It then develops into an obscure tragic comedy and gives food to those who love
Pentax-bashing!
08-29-2020, 07:18 AM - 1 Like   #12
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QuoteOriginally posted by photogem Quote
Because of course they knew what the problem was!

Luckily you had this extended warranty!

In a way this "Explanation of Repairs" stating: "Aperture Replaced" is.... with all due respect.... sheer nonsense!
Maybe just some typo by an unexperienced person
but really:


The aperture (diaphragm) is in the lens! For sure no aperture was replaced!

Inside your Pentax is a "aperture-control-unit", also called "diaphragm-control-block"
To control/operate the aperture/diaphragm!

What they got right is "Firmware Update" and "Cleaning".



But then we have something which just is an invention: This mysterious 'resistor chip'

The circuit has been the same since even SLR days, just voltage changed a bit since DSLR days and the original Pentax *istD.

The solenoid is driven by a so-called solenoid-driver, sitting on the upper flexboard (T700).

This solenoid-driver is at the same time the powersupply (but more complex) and if damaged, the solenoid can not fire anymore.

The solenoid-driver is soldered with 48 tiny contacts onto the upper flexboard, unsoldering almost impossible, one just replaces the whole flexboard!

But this was hardly ever needed because luckily it very rarely got damaged!

It can get damaged though if one files/sands the plunger!


What ALWAYS happened was that the plunger of the solenoid got stuck due to magnetisation!

When the camera is not in use i.e. does not fire, the solenoid is in "pull" action, i.e.the plunger is pulled towards the permanent magnet and stays there.
And thus together with other factors (friction in the housing which acts as a bearing) it can jam, i.e. the counteraction of the 2 electromagnetic coils is not enough to release the plunger. That's all, Anything else is fabrication, invention, fairy-tales!

A different solenoid-driver could in a way work but would just be compensation (to ease a problem).
Nobody would do that, it would be idiotic!


What Ricoh did was modify the solenoid since late K-S2 production days and since then we had very few failures, the same applies to the K70.

Because this "dark-image-syndrome" (solenoid failure) has become something quite large (and now is way out of proportion) any failure gives rise to something like "they did it again"... "they could not solve it" etc. Which is not true but thats how human psychologie functions... it's called pattern or classical conditioning (Pavlovian behaviour)


I guess that those who repair now those rare failures chose to name the repair differently. I can understand this because it is an attempt to deflect something that blew out of proportion but to name it "Replacement of aperture" or "repair resistor-chip" is not very intelligent either!


But actually here in this forum we have a very different problem:

Some (without any technical background) try to deflect as well. Some just try to deflect from the solenoid and others try to invent fairy-tales.

Doing this they actually just cause more damage (to Ricoh/Pentax) because it is an odd kind of bending over backwards of real facts and thus trying to dilute.
It then develops into an obscure tragic comedy and gives food to those who love
Pentax-bashing!
Well, I don't know exactly what they did on the repair, I just reported what they wrote down on the form returned with the camera. It could have been written by someone who got the details wrong, I don't know. I did change one thing in the words I quoted - in one spot (but not both) where the word "aperture" appeared, they spelled it wrong, and I corrected that in the quote I posted here. And I won't know whether or not the repair is truly successful for some time, since that will only be apparent if the problem doesn't recur. It was only happening intermittently before, so just shooting off a few frames would not indicate whether or not the repair was successful. In any event, this is specifically why I got that extended 3-year warranty (for only $17!) when I purchased the K70. After having my K50 fail, I thought it was quite a reasonable insurance cost, even though at the time of purchasing the K70 it was unknown whether or not that model would be likely to have this same defect. However, I reasoned that if it did eventually develop the same defect, or some other defect due to a failing component, I would have at least some low-cost recourse. The bottom line is that I really liked the K50, and was willing to take the risk on the K70. Overall I'm glad I did. Unlike many people who have been posting on this issue, I am not angry with the Pentax/Ricoh company and abandoning the brand for selling us cameras with faulty components. I am quite happy with my K70 (of course, I'd be less so if I hadn't spent that $17). Do I wish they had learned from their early experience with solenoid failures and fixed the problem? Of course I do. However, there are two sides to that coin. Pentax has always been a brand that aims to hit a certain price/features point in the market, a "value oriented" and "enthusiast" point. They try to incorporate lots of features that appeal to informed, enthusiastic amateur photographers, at a high level of value for price, and and an overall affordable price. To achieve this strategy, sometimes their design and/or component selection has aspects driven by keeping cost controlled that results in failures over time. I'm sure they didn't plan on those failures, but this is a natural result of staying close to the edge of that constraint. If they designed the camera and sourced the components to prevent 100% the possibility of any failures, which they could do (their engineers are as smart as anyone else's engineers), they would end up with cameras with less features, less innovation, less things to go wrong, or with similar features but far more expensive. They would no longer have that Pentax positioning in the market, and I'd likely not be a customer. I'm just not going to spend 2X or 3X as much money for the camera (e.g. higher end Nikons and Canons), and I'm also not interested in the Nikon and Canon ho-hum lower priced cameras. I've handled some of the Nikon and Canon DSLRs at similar price points to the K70, they just don't have the same feel to me, I would not enjoy using them, and certainly don't have the features I've grown to appreciate in the Pentax. Also, other brands are not immune to component failures, even persisting over several models. So for me, I am continuing to use what I really enjoy, and to take the ups and downs as they come.
08-29-2020, 08:00 AM   #13
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QuoteOriginally posted by Transit Quote
My thoughts exactly.
I bought my daughter a new k50 now the apertures failed ...
I was looking at K-70 as a replacement

I was disappointed to tell her maybe she should dump Pentax and go mirrorless
No reason for her to go mirrorless.

The KP is an excellent camera; it costs just $200 more than the K-70 and has the same aperture control mechanism as the K-1ii does.
The K-50 is fully usable as a 'manual' camera - I got an FA 28-105, which makes my K-30 fully usable in 'green button' mode.
08-29-2020, 11:28 AM   #14
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QuoteOriginally posted by OldChE Quote
Well, I don't know exactly what they did on the repair, I just reported what they wrote down on the form returned with the camera. It could have been written by someone who got the details wrong, I don't know.
The language used on your form is the same used on some previous repair statements for K-70; those resulted in some discussion regarding the "resistor chip". Its existence and any significance is unacceptable in some circles, hence the comment in protest.


Steve
08-29-2020, 04:42 PM   #15
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QuoteOriginally posted by photogem Quote
But actually here in this forum we have a very different problem:

Some (without any technical background) try to deflect as well. Some just try to deflect from the solenoid and others try to invent fairy-tales.

Doing this they actually just cause more damage (to Ricoh/Pentax) because it is an odd kind of bending over backwards of real facts and thus trying to dilute.
It then develops into an obscure tragic comedy and gives food to those who love
Pentax-bashing!
But then we have something which just is an invention: This mysterious 'resistor chip'
At one time, everyone understood what a "resistor" is, a small device with stripes on it - but they were not correct even then. I still remember a time in the 1960's when my Dad gave up on a B&W TV they had purchased in 1950 when my Mother was pregnant with my sister, and - living in the Chicago area as we did - it gave her something to watch. The TV was basically fine, but he could tell that a "resistor pack" had blown, and he had no idea what to purchase to replace it. By the time I was teaching in the 1980's, there were 'blocks' which looked like ICs but provided certain values of resistance. I am not certain what is available now, but I am quite certain that circuit designers could order connections or devices that would provide certain values of resistance. Thus, I agree with Stevebrot's choice of wording - we do not know exactly how the aperture control circuit is constructed, but I would not be so fast to reject Pentax's wording ..... they are the one who did the work.
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