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03-15-2019, 10:41 AM   #1
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Any KP's with Aperture Block Failure?

I'm fairly angry that after aperture block fails in K-30 and K-50 -- maybe K-S1 also -- that the K-S2 continued to use the same defective "green" mechanism from China. My K-S2 failed more than a year ago. Did the KP use the same defective aperture mechanism? With no K-3iii any reasonable time soon, I've no choice but the KP. Don't want this defect again.

03-15-2019, 10:48 AM   #2
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The KP does not have the same aperture block design. (But the K-70 does. Hopefully with a better solenoid.)
03-15-2019, 11:14 AM   #3
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Thanks!

QuoteOriginally posted by THoog Quote
The KP does not have the same aperture block design. (But the K-70 does. Hopefully with a better solenoid.)
Thank you! Good to know. With my lens investment, I have to stay with Pentax. No choice but the KP. Mark
03-15-2019, 01:18 PM - 1 Like   #4
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QuoteOriginally posted by Marktax Quote
I'm fairly angry that after aperture block fails in K-30 and K-50 -- maybe K-S1 also -- that the K-S2 continued to use the same defective "green" mechanism from China. My K-S2 failed more than a year ago. Did the KP use the same defective aperture mechanism? With no K-3iii any reasonable time soon, I've no choice but the KP. Don't want this defect again.
If there is a problem, KP owners are being VERY quiet about it.

As noted above, conventional wisdom at present is that the KP uses a controller similar to that in the K-3/K-3II and K-1.


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03-15-2019, 01:38 PM   #5
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It seems pretty obvious from the bulge on the KP body that it is using a similar motor as with the K-7,K-5, and K-3 bodies.

Compare camera dimensions side by side

You can see the motor used on the K-5 control block in the second and last photos in this post. You can see how the bulk of the motor and worm gear accounts for the shapes on the KP body.

https://www.pentaxforums.com/forums/114-maintenance-repair-articles/306083-k...ml#post3404196

Last edited by Not a Number; 03-15-2019 at 05:19 PM.
03-15-2019, 05:36 PM   #6
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QuoteOriginally posted by THoog Quote
The KP does not have the same aperture block design. (But the K-70 does. Hopefully with a better solenoid.)

Are you sure that K-70 does? As far as I know, nobody confirmed it ...
03-15-2019, 06:19 PM   #7
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QuoteOriginally posted by stevebrot Quote
If there is a problem, KP owners are being VERY quiet about it.

As noted above, conventional wisdom at present is that the KP uses a controller similar to that in the K-3/K-3II and K-1.
I don't believe it is just conventional wisdom. I can't find it right now, but I remember a Ricoh spokesman confirming at one of the conferences that KP used aperture control from K-3 family.


Last edited by reh321; 03-19-2019 at 08:03 AM. Reason: added word "just"
03-15-2019, 06:32 PM - 4 Likes   #8
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QuoteOriginally posted by Marktax Quote
No choice but the KP. Mark
...but a good choice, Mark.
The KP is mainly maligned by those who believe it was always meant as a K3ii replacement.
There is no other reason to malign it.
I love mine.
03-15-2019, 06:36 PM   #9
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QuoteOriginally posted by cport Quote
Are you sure that K-70 does? As far as I know, nobody confirmed it ...
If you look at the photos of the inside of a K-70 (registration required to view) on the German pentaxians.de forum you can see the K-70 uses a redesigned diaphragm control block that uses a the same or similar looking solenoid as the K-30/50/K-S1/K-S2.

Tutorial - Reparatur Pentax K-70 Blendensteuerung Solenoid ? Pentaxians

The solenoid body on the earlier cameras is parallel with the lens mount. On the K-70 the solenoid is at a 45° angle. One forum member said that Ricoh told him and another member that the K-70 uses a different mechanism from the earlier models.
03-15-2019, 06:58 PM   #10
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Not a number: well, this is what I said. Nobody confirmed that the aperture problem is a problem for K-70 as well.
03-18-2019, 08:37 AM   #11
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QuoteOriginally posted by Not a Number Quote
If you look at the photos of the inside of a K-70 (registration required to view) on the German pentaxians.de forum you can see the K-70 uses a redesigned diaphragm control block that uses a the same or similar looking solenoid as the K-30/50/K-S1/K-S2.

Tutorial - Reparatur Pentax K-70 Blendensteuerung Solenoid ? Pentaxians

The solenoid body on the earlier cameras is parallel with the lens mount. On the K-70 the solenoid is at a 45° angle. One forum member said that Ricoh told him and another member that the K-70 uses a different mechanism from the earlier models.
The solenoid being in a 45° angle would not be able to work!
Better have a closer look at the posted photo there

Maybe you can notice that there are no screws nor a plunger on the solenoid!

The person who did the repair unscrewed it to take the plunger off.

If you would have followed this thread (just be looking at it, no need to understand, pics speak so-to-say for themselves) you might have come across
This foto showing the solenoid in position.

The guy there did the "dreaded" grinding method, in the Pentax K30 part I shall post soon some photos showing why this sanding method is not to be recommended: The plunger when in action tilts with a noticable degree and brings too much force to the complicated mechanism.

If one undertakes the repair, then best with the white "made in Japan" solenoid only.
03-18-2019, 02:56 PM - 1 Like   #12
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QuoteOriginally posted by Marktax Quote
Thank you! Good to know. With my lens investment, I have to stay with Pentax. No choice but the KP. Mark
I have the K-S2, a very nice little camera, a lot of camera for being so small and light, and so far no problems. But I now also have the KP. I bought mine in silver and I love it. You will not be sorry with that choice! A great controls set, and a terrific modular design with its various grips and optional battery grip. 5-axis SR, fine build quality, numerous other updated refinements.

If you like really good images right out of the camera, the KP does an outstanding job. Just be sure to implement "Fine Sharpening" in the Custom Image menus.
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