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05-26-2017, 09:51 PM   #571
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That was a tedious read

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You can add my k-50 to the list at about 2.5 years. It currently has 4,925 shutter clicks, but I have been using it with a manual lens for a few months so you could probably shave a few hundred off that number. I have an ist-ds but not too chummy with the idea of taking it apart as it works a charm with over 10,000 clicks. Could be a sentimental attachment, as well. I have my eye on a few auctions for donor cameras, but might hit up some of the local pawn shops in the morning. For no more than I use it for, I could probably live with manual lenses. I get better control that way, anyway. It just kind of hurts my feelings that my *ist still performs perfectly and my pretty new-ish pet is in less than optimal functioning condition. I paid about the same for the k-50 new as I did the ist so I suppose it is reasonable that I expected all of the essentials to work about as long. If/when - I will update.


Last edited by Unregistered User 8; 05-26-2017 at 10:15 PM.
05-26-2017, 10:38 PM - 5 Likes   #572
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Update: my K-50 is back in my hands after Ricoh agreed to fix the aperture block failure out of warranty
As expected it works perfectly, I only paid for shipping one way, and they even have the thing a good cleaning.
06-08-2017, 02:48 PM   #573
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QuoteOriginally posted by Will in Seattle Quote
Update: my K-50 is back in my hands after Ricoh agreed to fix the aperture block failure out of warranty
As expected it works perfectly, I only paid for shipping one way, and they even have the thing a good cleaning.
Wow, that's awesome news, and lucky for you. I wonder if Ricoh will do this for everyone that complains? Or just issue a recall?
06-09-2017, 04:36 AM   #574
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When I asked a Pentax rep, I was told in so many words, get lost, out of warranty. It's cost me about $140.00 so far to have a 3rd party repair. Hopefully, Ricoh has turned a leaf and will repair future failures for their customers even though out of warranty as this is a known failure for a certain segment of their cameras.

Happy for you!

06-13-2017, 04:00 AM   #575
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Hi, late but my K-30 also started having this problem after ~4 years and ~33k shots. I made some quick temporal solution described here K30 random underexposure problem - Page 9 - PentaxForums.com but the problem is back and I have to repair it regular way. Then I found this interesting thread and also another one with photodoc. of repair on this forum that I will try.
Thos who followed this repair instructions can you tell me if your cameras are still working or if the problem appeared again? I found some solenoid replacement on ebay for 39$+post Pentax K-30 K-50 Genuine Aperture Solenoid Plunger Part - Made in Japan - | eBay - is it OK or faulty one?
I read a lot but I still have suspection about the true failure reason. It seems to me not logical, that the magnetic flux in the solenoid increased during the age. I would expect the opposite. If the coil heats up significantly during operation (esp. long exposures) it can affect neodymium magned that it will loose some magntism. Neodymiums are very strong but sensitive to temperature, maybe temp over 80C could cause partial damage to them. Can somebody do some measurement of magnet power to compare failing aperture mechanism and new mechanism? Is there really increase of magnetic power? Other reason could be caused by the coil if loosing it's power - by inter-turns short circuits due to overheating and insulation breakdown or the electronic don't push enough current to the coil. Did someone took the ampermeter to measure coil current on working and failing camera if there's a difference?
06-15-2017, 05:03 AM - 1 Like   #576
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QuoteOriginally posted by RayeR Quote
Hi, late but my K-30 also started having this problem after ~4 years and ~33k shots. I made some quick temporal solution described here K30 random underexposure problem - Page 9 - PentaxForums.com but the problem is back and I have to repair it regular way. Then I found this interesting thread and also another one with photodoc. of repair on this forum that I will try.
Thos who followed this repair instructions can you tell me if your cameras are still working or if the problem appeared again? I found some solenoid replacement on ebay for 39$+post Pentax K-30 K-50 Genuine Aperture Solenoid Plunger Part - Made in Japan - | eBay - is it OK or faulty one?
I read a lot but I still have suspection about the true failure reason. It seems to me not logical, that the magnetic flux in the solenoid increased during the age. I would expect the opposite. If the coil heats up significantly during operation (esp. long exposures) it can affect neodymium magned that it will loose some magntism. Neodymiums are very strong but sensitive to temperature, maybe temp over 80C could cause partial damage to them. Can somebody do some measurement of magnet power to compare failing aperture mechanism and new mechanism? Is there really increase of magnetic power? Other reason could be caused by the coil if loosing it's power - by inter-turns short circuits due to overheating and insulation breakdown or the electronic don't push enough current to the coil. Did someone took the ampermeter to measure coil current on working and failing camera if there's a difference?
I had repaired 4 x K30's and 1 x K50: all five still work!
2x K30 are with family, 1 is my own backup.
The 2 other K30/50's are in hands of people I know.

With 1 K30 I made the test to just exchange the tiny magnet (I guess yes, this is a neodym): No luck!
I also just exchanged the horseshoe: No luck either!
Only when the complete solenoid was exchanged against the white version it worked perfect.

To apply an amperemeter to measure coil current would be too much work, one would have to solder a cable from the camera to an adapter to the meter and then back from the meter to the second pin of the solenoid. I also don't know if my meter would be quick enough to measure burst current.
I only can guess, that one would need a special sensitive meter to do so.

I just would not want to solder too much on the K30 or the solenoid.
06-18-2017, 01:27 PM   #577
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The Ebay part seller is blaming the Chinese, we see a lot of such bigotry.

The blame is firmly and solely on Pentax END OF STORY or PERIOD as you Americans say!!!!

If mine fails I will demand Pentax fix it.

06-18-2017, 11:57 PM   #578
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larger shutter

QuoteOriginally posted by nocturnal Quote
The Ebay part seller is blaming the Chinese, we see a lot of such bigotry.
Why bigotry?
it is this Chinese part which fails. I had 5 of them in my hands, all five proved to be of inferior quality.


QuoteOriginally posted by nocturnal Quote
The blame is firmly and solely on Pentax.... END OF STORY or PERIOD as you Americans say!!!!
First of all, it is not Pentax but Ricoh. The solenoid was first used in the K30, which was fully under Ricoh (since 2011, the K30 came out 2012
but might have been developed during Hoya-times, K50 and K500 are almost similar, so one can guess, that the K-S1 was the first K-Series
developed fully under Ricoh... same solenoid)

Second: Ricoh (or Hoya) would have tested the chinese green solenoid. It was only after few years that the failure presented itself.
So yes, the manufacturer of the solenoid is to be blamed first. Ricoh and their policy second.

But we also know, that many modern parts such as electrolytic capacitors in PS's of for example TFT monitors only last about 2 years.

QuoteOriginally posted by nocturnal Quote
If mine fails I will demand Pentax fix it.
Strange demand. Your K30 is how old? In UK you have 2 years warranty. So how on earth are you going to demand
that Ricoh fixes it?

Last edited by MarkJerling; 06-20-2017 at 02:18 PM. Reason: Profanity and rude comment removed.
06-19-2017, 08:07 AM   #579
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Do'h! It looks like my black K-50 might be on its way to a busted solenoid. At about 26,000 shots, for the first time ever, it gave me 1 slightly underexposed frame. It wasn't completely dark, but I shot a bunch of similar shots with the same settings under the same light & noticed that the 1st shot was a bit darker. Hopefully it was a fluke. I guess I'll see as time passes by.

With a few QC issues that I have been reading about on the forum like sudden complete failure with a few K-3 cameras & this solenoid issue on the K-50/30 & even some K-S1/S2 bodies, it makes me wonder if I really want to wait for the upcoming APS-C flagship or get a K-3II instead. It seems like the K-3II is just about issue free. Hmmmm.......
06-19-2017, 10:28 AM   #580
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QuoteOriginally posted by The Squirrel Mafia Quote
Do'h! It looks like my black K-50 might be on its way to a busted solenoid. At about 26,000 shots, for the first time ever, it gave me 1 slightly underexposed frame. It wasn't completely dark, but I shot a bunch of similar shots with the same settings under the same light & noticed that the 1st shot was a bit darker. Hopefully it was a fluke. I guess I'll see as time passes by.

With a few QC issues that I have been reading about on the forum like sudden complete failure with a few K-3 cameras & this solenoid issue on the K-50/30 & even some K-S1/S2 bodies, it makes me wonder if I really want to wait for the upcoming APS-C flagship or get a K-3II instead. It seems like the K-3II is just about issue free. Hmmmm.......
Go for the K5iis and you will be in peace..
06-19-2017, 11:00 AM   #581
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QuoteOriginally posted by Jeff Lopez Quote
Go for the K5iis and you will be in peace..
It's a great camera & all, but I refuse to pay more than $300 for a used one or more than $450 for a new one. They were being sold for $450 at B&H back in February or so of 2015. The problem is they're all overpriced on eBay & on this forum.

I'd rather get a K-70 over a K-5II/5IIs. It's basically the same thing as the K-5IIs sans the "pro" build, but it has other newer tech & feature not available in the K-5IIs & it can use the KAF4 lenses. I still prefer the K-3II over the K-70, though.

I was about to buy the Pentax DA 10-17mm lens, but instead of that I'm just going to wait & see what Pentax does with their upcoming APS-C flagship. Supposedly we should know something around late August or early September. That camera either make it or break it for me.

I'm still gonna keep using this K-50 body until it fails completely. I have another red one that is going strong.
06-24-2017, 08:15 PM   #582
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I'm hoping Pentax Canada will be able to help me out and repair my K50 out of warranty, my K50 recently developed the aperture block/motor fail issue as well, at 13,000 shutter count, it's so upsetting as now I don't know when the photo will not turn out black!!! I've sent off an e-mail to Pentax Canada and let's wait and see.
07-05-2017, 07:55 AM   #583
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Decided to remove this message as I've since discovered the information in it is wrong (as can be seen from next post)

Last edited by jjnevis; 07-06-2017 at 02:40 PM. Reason: Updated information
07-06-2017, 01:53 PM   #584
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QuoteOriginally posted by jjnevis Quote
My K50 also developed the aperture block (black image) issue and was just out of warranty. I googled a bit and came up with what seems to be called the "Russian fix" or something like that. With a bit of trepidation I thought I'll have a go at fixing it myself and can confirm that it's actually pretty easy and (touch wood) seems to have solved the issue for me.

I read a few forum threads, but was finding it difficult to determine exactly what the issue is, or how it is definitely fixed. I decided to crack on and see if I would figure it out once opened up. I more or less followed this youtube clip: how to fix Pentax K50 and K30 with aperture problem - YouTube which is very helpful.

When filing down the D shaped core of the electromagnet I simply rubbed the 2 small flat ends simultaneously on a fine piece of wet and dry until it no longer stuck magnetically to the other end once inserted back into the coils. This is quite easy to test before re-assembling it. So, I surmised that the correct operation was that since the aperture actuator pin is spring loaded in the down position, that's where it should be "at rest" and when the coil is energised the two metal parts of the core magnetise and draw together pulling the pin up. Once the coil is de-energised, the two metal parts of the core separate since the pin is spring loaded, back to the original position. The bottom line is that it is now working very well and I've not had a single "black image" since, whereas before I fixed it, the camera was essentially un-usable.

Note: When putting the casing back on - be careful to locate the auto-focus selector switch correctly (there's a little pin that needs to find the right slot), otherwise you'll have to take it apart again to fix! (a little lesson learned). Also, be careful to put all the screws back in the correct place, using a diagram as suggested in the video is a good idea. A couple of the screws are under rubber grips that need to be pulled back to reveal.

Pretty chuffed to have my K50 back in action - just hope nothing else goes wrong! Also, my opinion is that it's definitely a design flaw and should be fixed by Pentax/Ricoh without question - their reputation is on the line here and I have to say I would probably recommend people looking at the lower end DSLR market to avoid Pentax because of this.

UPDATE!!! Issue is NOT fixed, aperture is now on fully open for ALL images regardless of what the camera sets it to, whereas before "fix" I think it was fully closed (hence dark) for all images. Think I'll need to send it off after all.
Well, your first message must have been done in a hurry.

As you explained quite well how the actuator works: What is not connected now so the aperture does remain fully open?
You explained it. Before sending it in, open it again (but apply more patience) and check this spring load!
07-06-2017, 02:38 PM   #585
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QuoteOriginally posted by photogem Quote
Well, your first message must have been done in a hurry.

As you explained quite well how the actuator works: What is not connected now so the aperture does remain fully open?
You explained it. Before sending it in, open it again (but apply more patience) and check this spring load!
Apologies photogem, you're right - I've removed the original message since the info was incorrect (much to my disappointment since I've still got bust K50! Ahhh!)
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