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01-18-2017, 11:36 AM - 1 Like   #286
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QuoteOriginally posted by paolo11 Quote
Now, you can buy an entire new aperture block on Ebay for 39.00 shipped from Japan, perhaps this will give you some life until it fails again.
I don't find anybody in Japan selling the entire block new. There is someone in the US selling the solenoid only scavenged from K-r and K-x bodies for $39. The entire block would include the controlling circuit and levers.

Pentax K-30 K-50 Genuine Aperture Solenoid Plunger Part - Made in Japan - | eBay


QuoteOriginally posted by paolo11 Quote
That's exactly the problem I had with the K50 which uses the same block as the K30.
And the K-x, K-r, and K-500, K100D, and *istD use the same solenoid if not the entire block. Most likely the K-01, K-m, K110D use it too.

01-18-2017, 01:04 PM   #287
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k30 aperture block | eBay

here's the link for the K30/K50 aperture block

http://www.ebay.com/sch/i.html?_sop=10&_armrs=1&_mdo=Sporting-Goods&_pcats=1...sacat=0&_oac=1

---------- Post added 01-18-17 at 03:11 PM ----------

QuoteOriginally posted by Not a Number Quote
I don't find anybody in Japan selling the entire block new. There is someone in the US selling the solenoid only scavenged from K-r and K-x bodies for $39. The entire block would include the controlling circuit and levers.

Pentax K-30 K-50 Genuine Aperture Solenoid Plunger Part - Made in Japan - | eBay




And the K-x, K-r, and K-500, K100D, and *istD use the same solenoid if not the entire block. Most likely the K-01, K-m, K110D use it too.
okay, my bad,it's the plunger part that's been refurbished. sorry.

Last edited by paolo11; 01-18-2017 at 01:06 PM. Reason: link
01-21-2017, 03:35 PM   #288
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Bad news:


Heating up the camera just is a temporary solution.
Somebody did confirm this method but after about 50 shots my K-S1 went to black frame status.


So I did it the "russian way".


https://www.pentaxforums.com/forums/184-pentax-k-s1-k-s2/338046-k-s1-aperture...ml#post3888699 post #7
01-21-2017, 07:16 PM   #289
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QuoteOriginally posted by marabella Quote
bad news:


heating up the camera just is a temporary solution.
Somebody did confirm this method but after about 50 shots my k-s1 went to black frame status.


So i did it the "russian way".


https://www.pentaxforums.com/forums/184-pentax-k-s1-k-s2/338046-k-s1-aperture...ml#post3888699 post #7
and? What was the oucome

---------- Post added 01-21-17 at 09:20 PM ----------

Have to tell you just picked up a Pentax 10D for parts but it works just fine. Here is the kicker, it has 162000 accusations on it .I know cause i went to this site Camera Shutter Count and it told me so.But no big deal it works fine and it only cost me $50 so cant complain. But 162000 and counting got to love it

---------- Post added 01-21-17 at 09:23 PM ----------

QuoteOriginally posted by niceshot Quote
and? What was the oucome

---------- Post added 01-21-17 at 09:20 PM ----------

Have to tell you just picked up a Pentax 10D for parts but it works just fine. Here is the kicker, it has 162000 accusations on it .I know cause i went to this site Camera Shutter Count and it told me so.But no big deal it works fine and it only cost me $50 so cant complain. But 162000 and counting got to love it
SURVEY: What's your shutter actuations count? here read this, And you will feel robbed

01-22-2017, 06:44 AM   #290
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Ks1 heating

The problem with the Russian and other filings of the horse shoe plunger, or whatever you want to call it, is what's the correct amount to file? I read one case where one owner filed too much. Too little, no change, too much, won't work, so it seems.

I paid to have mine fixed by a long-time camera repairer/tinker, and so far so good, gives a year warranty. He won't reveal, at this time, what he did. After the repair, he kept it for a couple of days for testing.

If I had to do it again, knowing what I know now, I would have fixed it myself as you can buy the "plunger" for 39.00 shipped if you screw up.

The design problem from Pentax is pitiful.
01-22-2017, 06:46 AM   #291
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Ks1 heating

The problem with the Russian and other filings of the horse shoe plunger, or whatever you want to call it, is what's the correct amount to file? I read one case where one owner filed too much. Too little, no change, too much, won't work, so it seems.

I paid to have mine fixed by a long-time camera repairer/tinker, and so far so good, gives a year warranty. He won't reveal, at this time, what he did. After the repair, he kept it for a couple of days for testing.

If I had to do it again, knowing what I know now, I would have fixed it myself as you can buy the "plunger" for 39.00 shipped if you screw up.

The design problem from Pentax is pitiful.
01-22-2017, 04:50 PM   #292
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QuoteOriginally posted by paolo11 Quote
The problem with the Russian and other filings of the horse shoe plunger, or whatever you want to call it, is what's the correct amount to file? I read one case where one owner filed too much. Too little, no change, too much, won't work, so it seems.

I paid to have mine fixed by a long-time camera repairer/tinker, and so far so good, gives a year warranty. He won't reveal, at this time, what he did. After the repair, he kept it for a couple of days for testing.

If I had to do it again, knowing what I know now, I would have fixed it myself as you can buy the "plunger" for 39.00 shipped if you screw up.

The design problem from Pentax is pitiful.
So you are certain now you know specifically what the problem is?? Please do tell us.

BTW - you are aware that this same part is used in various other contexts - without any known issues.

01-22-2017, 05:44 PM   #293
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SURVEY: What's your shutter actuations count?. Read this and you will cry
01-24-2017, 05:06 AM - 4 Likes   #294
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Here how to fix K50:
01-24-2017, 07:47 PM   #295
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QuoteOriginally posted by mateusbschwaves Quote
Glad to see someone made a video for this fix, excellent job!
01-25-2017, 07:03 AM - 2 Likes   #296
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How I did it myself & Where to find the replacement part needed.

Hi guys,

after watching the great video above https://www.pentaxforums.com/forums/151-pentax-k-30-k-50/321871-k-30-k-50-ape...ml#post3891300 and some researching, I fond that the culprit for our failure here (the solenoid) is in fact a relatively common part. For example, the thingie that clicks open your laptop's CD drive possibly is that exact part. So I raided an old CD drive and found and unsoldered the solenoid there.

Then, like shown in the video, I opened the camera. To pull away the rubber covers, I used a guitar pick. As stated in the video, the biggest problem is actually pulling out the camera's front cover. Luckily though, there are no prone-to-break snapping lugs. I started at the grip side, which comes off by pulling and wiggling, and then wiggle off the other side, until the whole thing came off the lens mount. The rubber cover for the video/usb plug is hooked up behind the rubber cover on the left side of the camera (left when looking through the viewfinder). After that, I unsoldered the old actuator, unscrewed it, put in the salvaged one, which is somewhat fiddly, fastened it, soldered the wires to it, and checked the function.

When doing the fine fiddly work, like soldering, I used loupe spectacles and a headlamp. I used a temperature-controlled radio soldering iron, which actually is just a little bit to clumsy for that kind of work. Be careful not to damage the battery compartment or the PCB mounted to it with the soldering iron.

The original solenoid from the camera had no signs of wear or tightness, in fact, it was easier to pull the plunger away from the magnet than it was on the part from the CD drive. So I think the problem isn't that the plunger gets magnetized (it was not, in fact) or that there's developing some sort of stiction in the actuator, but that the electromagnet builds up to little power to counteract the permanent magnet. This would also explain why changing the battery type affects the problem (my camera only showed it with the LiIon battery).

After replacing the solenoid, I cleaned all the edges and sealing, especially round the lens mount with a q-tip, then I put the front back on. Be careful to align the AF switch correctly, on my first attempt, it ended up above the slot where it should have been and thus wouldn't move to the MF position; position the camera upright, tripod mound downwards, so that the inner part of that switch doesn't move inadvertently upwards towards the prism.

I carefully tightened all screws while pressing the front cove in place, minimizing the gaps. Turn every screw counterclockwise first until you feel it click into thread, that way you won't accidentally create new threads in plastic screwholes. I pressed the rubber covers back in place, which seems to work w/o reglueing.

After refitting the bottom cover, I blew out the sensor and mirrorbox, lint is unavoidable, I think.

When doing the repair, watch the video carefully. You don't have to remove the top cover (or unsolder wires there!) like stated in this forum, this is dangerous and unnecessary. You don't even have to unscrew the screws at the strap attachments (so the strap can stay attached, too).

So far, the camera is working perfectly like it should be. If you have some experience doing fine work, if you know how to solder, and if you can find an old laptop CD drive, this is for you, give it a try and report back.
01-25-2017, 07:14 AM   #297
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Addendum: I forgot to say that the camera is a K-50.
01-25-2017, 11:51 AM   #298
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QuoteOriginally posted by sys3175 Quote
When doing the repair, watch the video carefully. You don't have to remove the top cover (or unsolder wires there!) like stated in this forum, this is dangerous and unnecessary. You don't even have to unscrew the screws at the strap attachments (so the strap can stay attached, too).
Yes, it is competely unnecessary to de-solder the top cover on either the K50 or K30.
On the K30 however it easier for clearance if you unscrew the top cover and pull it out of the way half an inch or so. It may make removing the front cover easier as well. (I never tried removing the front cover with the top cover still screwed down).

Great you got yours fixed. I fixed mine with a replacement solenoid from a donor K30. But harvesting old CD drives is a great idea. Should be plenty of those knocking around cheap!
01-25-2017, 05:24 PM - 1 Like   #299
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QuoteOriginally posted by sys3175 Quote

The original solenoid from the camera had no signs of wear or tightness, in fact, it was easier to pull the plunger away from the magnet than it was on the part from the CD drive. So I think the problem isn't that the plunger gets magnetized (it was not, in fact) or that there's developing some sort of stiction in the actuator, but that the electromagnet builds up to little power to counteract the permanent magnet. This would also explain why changing the battery type affects the problem (my camera only showed it with the LiIon battery).
So here's my understanding of how it works:

The lens aperture lever is sprung loaded and held open in tension when you attach the lens.

When you want to take a picture the tension is released and the aperture starts closing.

The movement is measured by an optical sensor and needs to be interrupted at varying distances depending on the chosen aperture.

The horse shoe moving outwards is what stops the aperture closing any further, but in failed cameras it never moves.


It's weird that the replacement part has a stronger magnet yet still works. Does it have more coil windings? Also is the purpose of the permanent magnet to pull the horse shoe back in? Isn't it spring loaded and wants to return anyway?

Are you talking about AA lithiums or the DL-I109?
01-25-2017, 06:30 PM   #300
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Would have been nice if the video showed the part in operation.
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