Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
06-22-2017, 01:51 PM   #46
Moderator
Not a Number's Avatar

Join Date: Mar 2012
Location: Venice, CA
Posts: 10,508
QuoteOriginally posted by tsvetan Quote
This second body developed the same problem again around 9 K shots and since then I have been shooting only manually.
I used the russian method, I filed some material off the U part and now it works again! Thank you so much! This is a great community!
So you have a K-30 with a white solenoid that failed? So I guess it is not only the green solenoids that cause the failure and the same modifications to the metal part of the white solenoid seems to correct the problem.

06-22-2017, 02:52 PM   #47
Loyal Site Supporter
Loyal Site Supporter
THoog's Avatar

Join Date: Aug 2012
Location: North Carolina
Photos: Gallery | Albums
Posts: 3,685
QuoteOriginally posted by Not a Number Quote
So you have a K-30 with a white solenoid that failed? So I guess it is not only the green solenoids that cause the failure and the same modifications to the metal part of the white solenoid seems to correct the problem.
On my monitor, his solenoid is a pale green color.
06-22-2017, 03:00 PM   #48
Veteran Member




Join Date: Jun 2015
Location: South West UK
Photos: Albums
Posts: 1,493
QuoteOriginally posted by THoog Quote
On my monitor, his solenoid is a pale green color.
Ha...it's the dress argument again. Yep definitely green here too.
06-22-2017, 08:13 PM   #49
Junior Member




Join Date: Dec 2016
Posts: 47
Is there a recommended video or stills sequence that best shows this solenoid repair process?

I've just now watched a few videos on YouTube and they weren't comprehensive enough for me.

I'm reasonably handy with a screwdriver and soldering iron, but I do best when I have good images and instructions to work from.

Oops - sorry - my camera is a K50.


Last edited by pentaprickle; 06-22-2017 at 08:15 PM. Reason: Ommission
06-25-2017, 01:32 PM   #50
Loyal Site Supporter
Loyal Site Supporter




Join Date: Oct 2009
Location: north Georgia mountains
Posts: 691
QuoteOriginally posted by Clover-Leaf Quote
After sitting idle for a few months, I fired up my K-30 to find it was taking black photos only. After some basic troubleshooting, it was obvious that the aperture was closing down all the way, no matter what the camera said it should be. So some internet searches led me here because it seems the only technical article is from a Russian site. One of the members here was good enough to translate it for us, so at least I had a basic understanding of what to look for.

Since I have a long background in electronics troubleshooting and working on small delicate items, I decided to dig into my K-30. It was useless and not worth anything as it was, so what's to loose? Here I'll explain how I did it, and maybe help others that find themselves in a similar situation.

So let’s get started. For the sake of clarity, the right and left sides of the camera are when viewed from the front. Also, work with a body cap to protect all the innards, and keep small parts from flying in there.

1) Remove the bottom plate: Remove all the screws holding the bottom plate. Make careful note of which screw came from which hole. Some screws are fine thread for metal and some are coarse thread for screwing into plastic. There are 3mm, 4mm, 6mm, 7mm and 10mm screws. While you’re at it don’t forget the silver screw down inside the battery compartment. There is a total of 13 screws.



2) Remove the top cover: WARNING: (I hate stupid warning messages, but this IS important, so DON’T take it lightly. The flash capacitor is directly under the PCB that you will be desoldering wires from on the right side, and areas near the PCB do have some “juice” that can give you a NASTY JOLT – one you won’t forget! Be very careful).

Slide the rubber eyepiece up to remove it. There are 2 screws under it that need to be removed. Remove the 2 screws just inside the loops for the neck strap. There is another screw on the right side just under the button for the pop-up flash. Now pop up the flash and remove the 3 screws inside the front. There is a total of 8 screws. The top cover is not difficult to remove at this point. A thumbnail pressed into the top cover seam is all that is needed to get it started. Be gentle. If you pull too hard and it suddenly pops off, the wires inside will most likely get ripped off their solder pads. There is a total of 6 wired to be unsoldered.

3) Unsolder the wires from the PCB on the right side. Position the camera as shown below to minimize the stress in the wire leads. Make note of their locations and unsolder them. (Remember that warning above????)

4) Remove the ribbon connector on the left side.





5) In case you lose track of where the wires go, this should help.

6) Remove the front cover: Remove the rubber grip on the right side of the camera. There are 2 screws underneath. Peel back the left rubber grip slightly and remove the first screw that appears. Lay the rubber back down – there is no need to remove it. Remove the other screw on the left side near the DC power jack. There is one more screw on the bottom between the projections for the lens and hand grip. There is a total of 5 screws. The front cover should pop off – there are no wires connected to it.



7) With the 3 covers removed, we can get to the solenoid. It’s just to the left of the large silver cross in the center of the photo. Unsolder the 2 wires. You will need a long small jewelers size Phillips screwdriver to remove the screw that holds it in place. Now just pick it out by the steel frame, not by the copper coils!



8) Here’s the culprit. The solenoid is shown in it’s activated position, locked in place, even though there is no power applied. When the solenoid is activated, the horse shoe shaped plunger (the bottom piece of steel) is pulled up into the 2 coils, as shown. This activates the arm that controls the aperture opening. The vertical slit in the top of the frame has a powerful neodymium magnet inserted into it. The problem is that the plunger is pulled in so far that the legs of the horse shoe hit the highly magnetized frame at the top of the solenoid. The magnetic pull is so great that the horse shoe plunger is locked in place very solidly. I didn’t think to measure the amount of force to pull the plunger back out, but it has to be at least a couple of pounds. That magnet is surprisingly powerful.





9) Since I didn’t want to make any permanent changes that couldn’t be reversed, I elected to fill in the gap at the bottom of the horse shoe, and then add another .25mm so it would bump the plastic solenoid coil form before the top end of the legs could get magnetically locked to the upper steel frame. So I filled the bottom of the of the horse shoe with solder and then carved it into shape with an x-acto knife (with a new blade) so the legs are now only 3.37mm long, as opposed to the original 3.87mm long.

10) At this point, I put it all back together by just reversing the whole procedure. The camera is taking fine pictures again, and for 0$$. Total time was about 3.5 hours. If you want to try this yourself, here are a few pointers:
Be patient and think things out.
Be gentle - it's a delicate item with even more delicate parts inside.
Have a large, clean and organized work area.
Spread out a clean bath towel over your work area - small parts do not bounce off of a towel.
Superby detailed instructions, supported by sharp and detailed photos: THANK YOU! Being as my K-30 is also gathering dust thanks to the aperture block failure, I will try this repair myself. With patience and no caffeine (plus that bath towel you recommend) it should go well. BTW there was a plus to the K-30's failure: It justified the purchase of a K-3 ... !

---------- Post added 06-25-2017 at 04:41 PM ----------

QuoteOriginally posted by GolNat Quote
Maybe instead of a return spring the magnet is used to return the plunger. The coil always seems to be "closed" (small aperture). Current is applied to the coil to increase the aperture to the needed amount and then the magnet returns the plunger to the "closed" state.

Seems like the tolerance is to close and it gets stuck and the coil is not strong enough to over come this. Possibly due to a weak battery and not enough energy to overcome the magnet.

Great write up by the way Clover-Leaf. If my K-50 ever developed the issue I was going to tear into it also and see what I could find, saves me the trouble.
I wonder if the design logic parallels that of solenoid valves on natural gas / propane appliances. In case of electrical power failure, these valves are designed to "fail safe", i.e. in a closed position. Electric current holds them open, mechanical spring pressure forces them closed when de-energized.
06-25-2017, 02:19 PM   #51
Senior Member
Nuno Almeida's Avatar

Join Date: Sep 2014
Location: Aveiro
Posts: 179
QuoteOriginally posted by Owltown Quote
Superby detailed instructions, supported by sharp and detailed photos: THANK YOU! Being as my K-30 is also gathering dust thanks to the aperture block failure, I will try this repair myself. With patience and no caffeine (plus that bath towel you recommend) it should go well. BTW there was a plus to the K-30's failure: It justified the purchase of a K-3 ... !

---------- Post added 06-25-2017 at 04:41 PM ----------


I wonder if the design logic parallels that of solenoid valves on natural gas / propane appliances. In case of electrical power failure, these valves are designed to "fail safe", i.e. in a closed position. Electric current holds them open, mechanical spring pressure forces them closed when de-energized.
It's the desired natural state, but that depends on application and design, you have both NC and NO valves, and relays and switches of all kinds, in this case it isn't a safety application, just probably the easiest and cheapest way the designers found to create the desired effect.
03-22-2018, 09:14 AM   #52
New Member




Join Date: Mar 2018
Posts: 1
Great description by Clover-Leaf and some variations

Thanks a lot to Clover-Leaf for this detailed and absolutley reliable description ! I have rarely seen such a fine documentation for solving a technical problem. This one has truely saved our K-50 with the described black picture and closed apperture problems. The sales person's only comment was to by a new camera after the few years of use .

I was scared by the idea to unsolder the leads to the top-cover and getting close to the flash capacitor and tried to aivoid this. As Clover-Leaf wrote, all the screws holding the top cover had to be removed; however, than I removed all the screws holding the front cover and lifted the top cover only a few mm - just enough to get the front cover out. The top cover was then put back in place and secured with a few screws until it had to be lifted again to get the front cover back in.

For the repair at the solenoid I chose a very mild removal of material approach. I wiped the horse shoe ends with aceton and pulled the top ends of the horse shoe 2 or 3 times over a piece of very fine (1000) sanding paper with its backside flatly placed on the table. It worked so far . Even though I unsoldered the solenoid from the connecting wires I guess that the horse shoe might even have been removed from the coil while still hanging on the wires.

Why did it work? I can only speculate ....

To me it looks as if the horse shoe can have two stable positions without current applied to the solenoid:
One position would be max. out. The field of the permanent magnet seems to be too low to pull the horse shoe in from that max out position. A short electric pulse applied to the coil in the right polarity to enhance the permanent magnet's field could be strong enough to pull the horse shoe in.
In the max in position the permanent magnet might be strong enough to hold the horse show in without any electric current applied. A short electric pulse in the polarity opposite to that applied before might counteract the field of the permanent magnet and might be the trigger to release the horse shoe. At least, after the repair I can use a small pin to push the horse shoe into either of the positions and it stays there without any electricity supplied to the camera. The problem why the horse shoe could not be released in my case might have been just the deposition of some traces of sticky and poorly volatile organics (possible evaporated over time from the coil???) on the horse shoe ends or that the ends of the external horse shoe had after 1000s of triggers been hammered so flatly against the internal horse shoe so that they just got stuck by exclusion of any air between them. Acetone and the fine sanding paper might have solved either of the problems.

Anyway: Success is what counts and Clover-Leaf's description is the essential document to do the repair. Thanks again for text and pictures!

04-04-2018, 09:16 AM   #53
New Member




Join Date: Apr 2018
Posts: 1
I have the same problem and I intend on trying to fix the camera by myself, since Pentax is not sold in Brazil, but the images on the first post are gone. Is there another guide with pictures?
04-10-2018, 10:07 AM   #54
Site Supporter
Site Supporter
Dewman's Avatar

Join Date: May 2012
Location: Idaho
Posts: 5,492
QuoteOriginally posted by patrick9 Quote
I had him fix mine.

My K-30 too! He did a superb job and had my camera back to me in two weeks! Same here.... $100.00 with a one year guarantee, too! I highly recommend him. His name is Mark.
04-25-2018, 12:49 AM - 1 Like   #55
Site Supporter
Site Supporter




Join Date: Apr 2015
Posts: 3,505
(Scroll down for update on how to discharge the flash-capacitor if you feel you need to!)
I'd like to add a few "modifications", which will result in

a) better and safer work
b) Modification to a few important steps

I have repaired many K30's and K50's now (not commercially, only family, friends etc.)
and know the steps now inside out:


QuoteOriginally posted by Clover-Leaf Quote
1) Remove the bottom plate: Remove all the screws holding the bottom plate. Make careful note of which screw came from which hole. Some screws are fine thread for metal and some are coarse thread for screwing into plastic. There are 3mm, 4mm, 6mm, 7mm and 10mm screws. While you’re at it don’t forget the silver screw down inside the battery compartment. There is a total of 13 screws.
Nothing to add, all fine


QuoteOriginally posted by Clover-Leaf Quote
2) Remove the top cover: WARNING: (I hate stupid warning messages, but this IS important, so DON’T take it lightly. The flash capacitor is directly under the PCB that you will be desoldering wires from on the right side, and areas near the PCB do have some “juice” that can give you a NASTY JOLT – one you won’t forget! Be very careful).
If you wish to discharge the flash capacitor, do it this way:

Use a 40/60/100 Watt old type lightbulb (with leads soldered onto it and then taped with insulation tape so when you touch it you won't jump up in awe:-) ) or a 1-1,6kOhms /5-10 Watt resistor. Lightbulb is better because it shows the discharge.

Discharge the flash-capacitor ONLY against the metal-ring which takes on the lenses because this metal ring is MINUS!

The Plus-wire you find directly on the capacitor, it is the first wire coming out of the capacitor itself facing this metal right, i.e. the left one!

This is much much easier than trying to discharge the capacitor using both the 2 wires coming out of it which is not recommended at all.
Space is too tight to do it.


An old analog multimeter instead of the lightbulb will do the trick as well: DC Position (important, i.e. not AC): Start with about 350V (or higher), then, when the voltage dropped down to 50V, switch over to the 50V (or closest) position of the meter.

UPDATE July 2018:

Read my post #730!



It is not necessary to discharge the capacitor.

The capacitor only charges if you switch the camera ON and pop-up the flash by pushing the flash-button.
You can pop-up the flash without charging the capacitor if the camera is not ON but the battery is inserted.
So just make sure, the camera was left for a while without use so the cap is discharging itself.
Then never pop-up the flash while the camera is ON!



BUT THEN:

QuoteOriginally posted by Clover-Leaf Quote
2) 3) Unsolder the wires from the PCB on the right side. Position the camera as shown below to minimize the stress in the wire leads. Make note of their locations and unsolder them. (Remember that warning above????)

4) Remove the ribbon connector on the left side.
NOT NEED TO TAKE THE TOP PART OFF!!! Only have it lose, i.e. all screws removed so you can lift the top part a tiny bit off!
This is important so you can later on take the front part off. Also you have better access to the solenoid itself, which you want to built out completly and exchange which I will explain later on.

NO NEED TO SOLDER ANY WIRES ON THE TOP PART!!!

NO NEED TO take the ribbon connector off!

WHY: I shall explain later on:

QuoteOriginally posted by Clover-Leaf Quote
2)
6) Remove the front cover: Remove the rubber grip on the right side of the camera. There are 2 screws underneath. Peel back the left rubber grip slightly and remove the first screw that appears. Lay the rubber back down – there is no need to remove it. Remove the other screw on the left side near the DC power jack. There is one more screw on the bottom between the projections for the lens and hand grip. There is a total of 5 screws. The front cover should pop off – there are no wires connected to it.
Fine, but remember to have the AF switch on green (AF-S), and when you install the front cover, make sure it still is on AF-S and the inner (main) switch is switched downwards! (So external part of this switch upwards on AF-S and internal part downwards. Or vice verca of course)

QuoteOriginally posted by Clover-Leaf Quote
2) 7) With the 3 covers removed, we can get to the solenoid. It’s just to the left of the large silver cross in the center of the photo. Unsolder the 2 wires. You will need a long small jewelers size Phillips screwdriver to remove the screw that holds it in place. Now just pick it out by the steel frame, not by the copper coils!
Here comes the first important modification:

Tiny hint: Not a Philips screwdriver, but those Japanese JIS are far superior

But then:

First buy the white Made in Japan Solenoid and ONLY USE that one in exchange.

This is the only permanent and save solution!

The filing or soldering method has led in several cases to unrepairable K30's and K50's, because the movement of the horseshow (which is filed or soldered) is after that less precise and can further damage the green cheap plastic material.

Find the white solenoid in the K10D, K100D, K200D, *ist models, K2000, K-x, K-r.
Some have used solenoids from earlier manual Pentax bodys, I have only found it save with the orig. *ist (manual version)
but found several critical solenoids in the MZ50, MZ6 and MZ7: Either with a stronger holding force or wrong polarity.
Latter isn't a problem if you either change the wires in polarity which then has to be done on the circuit-board itself.
Also don't get ANY blue solenoids from CD-Rom drives as some recommend: Those have usually 15ohms impedance instead of 30ohms. They might work for a while but the then too high power (due to half the resistance, i.e. more heat) the coils with eventually burn and you might end up with further damage!

Possibly also the Samsung GX1, GX2 and GX10 will have that solenoid.

Otherwise play save and buy it on ebay. Attention: there are sellers from Far East offering the green solenoid: Fingers away!

So if you have the right white solenoid: Don't solder the wires from the top part but only the two wires directly at the solenoid!

When you solder, use a soldering-iron with a very fine tip and if a non-temperature controlled unit then 10-15W max.!
If temperature controlled, power is seconcary, you can adjust the temperature to your liking, i.e. relativly low.

Last edited by photogem; 07-21-2018 at 03:55 AM. Reason: Update
04-25-2018, 06:28 AM   #56
Senior Member




Join Date: Jul 2012
Posts: 197
QuoteOriginally posted by photogem Quote
I'd like to add a few "modifications", which will result in

Find the white solenoid in the K10D, K20D, K100D, K200D, *ist models, K2000, K-x, K-r.
Possibly also all the Samsung version.
Or play save and buy it in ebay.
Photogem, thanks for this additional information on fixing K-30 etc.

Regarding the white solenoid, are any of the solenoids from film-era Pentax cameras (e.g., ZX-60, ZX-5n) good candidates for replacing the green solenoid? Is there a simple test for determining if a given white solenoid is an appropriate candidate for fixing the problem?
04-26-2018, 06:18 AM   #57
Site Supporter
Site Supporter




Join Date: Apr 2015
Posts: 3,505
QuoteOriginally posted by T Evergreen Quote
Photogem, thanks for this additional information on fixing K-30 etc.

Regarding the white solenoid, are any of the solenoids from film-era Pentax cameras (e.g., ZX-60, ZX-5n) good candidates for replacing the green solenoid? Is there a simple test for determining if a given white solenoid is an appropriate candidate for fixing the problem?
None of those you mentioned work, those are completly different solenoids, as well as in the MX5, MX5N.
I added more information in my orig. post, otherwise check on my previous postings, I have written a lot about it.
08-03-2018, 02:02 PM   #58
Senior Member




Join Date: Jun 2013
Posts: 120
First, thanks to Clover-Leaf and photogem for the instructions on how to do this repair yourself. I just completed replacement with the white solenoid on my K-30, and so far things are working properly again. I thought I would share my own experience (sorry, forgot to take pictures), in case it can help anyone else. It took me a little under an hour. I took my time and carefully followed instructions, so your time may vary.

- I went the route of ordering the white solenoid from ebay. Cost was $45.
- I followed Clover-Leaf's initial post with photogem's suggestions.
- I followed photogem's procedure for discharging the flash capacitor by activating the flash after removing the battery. Not sure if this was necessary. Also, my camera has been sitting for over a year due to this issue, though the battery was still partly charged
- I did not remove the top of the camera, per photogem's advice. Note that you still have to remove all the screws on the top part. See below for consequences/choices doing it this way.
- Make sure you label all screws as you remove them. They are different lengths, and you need to make sure you put the right ones in the proper spots when you reassemble. I drew a picture on a piece of paper for each step and scotch-taped the screws to each section. This worked really well and made reassembly a breeze.
- Removing the screws and disassembly are straightforward if you follow Clover-Leaf step by step, including the number of screws at each step (super helpful).
--- There is one possible typo in his directions. Step 1 says "While you’re at it don’t forget the silver screw down inside the battery compartment." This is not necessary; just the two screws on top of the compartment after you lift the cover are needed to be removed. (K-30 only; do not know other models)

- OK, here is where the big choice comes in: As I mentioned above, I chose to leave the top of the camera on (but still removed the screws). The consequence of this is that soldering, removing, and replacing the solenoid is a ROYAL PITA. You have to wiggle it into a very small space onto pegs, plus access to the retaining screw is tough. Soldering is inhibited by part of the case. I was able to do it, but took a lot of patience. Not the cleanest solder job, but I was careful to not drip onto other parts and it seems to work
--- I think if you remove the top, the solenoid is much easier to access. The trade-off is that you then need to deal with the wires in the top part, including un-soldering and re-soldering. I guess it depends on how good you are at soldering and how much time you are willing to put in for probably a cleaner job.

So far so good. Thanks again to Clover-Leaf and photogem.

Hope this helps anyone else trying this repair.

Last edited by Takumar55; 08-03-2018 at 02:32 PM.
08-03-2018, 04:07 PM   #59
Site Supporter
Site Supporter




Join Date: Apr 2015
Posts: 3,505
Thank you for thanking me and others, but again I have to correct errors which can lead to damage of the K30/50/500:


It is very important to unscrew the top part as well and to lift it just a few millimeters, that's all that is needed.
(I just repaired a K30 today for a friend.)

It is very much so, if you don't lift the top part, the removal and soldering of the solenoid is quite difficult as you experienced it!

Having the top part just that bit higher lifted up makes it much easier. But this is not all the reason:

You also get the front part much easier off!


Because it is interlinked with the top part.


You might even damage parts of both if you don't lift the top part!


So to be able to lift the top part, you need to follow all the instructions shown HERE with the difference of 3 screws for the k30 at the flash instead of the two of the K50 (and K500) and a tiny difference at this side were the "Video PC USB cable" is connected, this is easier with the K30.


And of course you have to unscrew the silver screw inside of the battery compartment!!!

Otherwise you will damage the top part when trying to lift it off!

So for gods sake, don't change instructions for the illusion that this might make things easier, it is the very opposite as you even described.
You were lucky that you did not do damage to your K30!
08-03-2018, 11:17 PM   #60
Veteran Member
altopiet's Avatar

Join Date: Sep 2010
Location: The Gem of the Karoo, South Africa
Photos: Gallery | Albums
Posts: 2,307
QuoteOriginally posted by photogem Quote
So for gods sake, don't change instructions for the illusion that this might make things easier, it is the very opposite as you even described.You were lucky that you did not do damage to your K30!
Wow, what an angry response, if he did it another way that worked, don't get so worked up.

It worked for him, and I'm sure everyone contemplating doing the job, knows it's not going to be a walk in the park. When the time comes I might rather try the minimal invasion route first, and only if it doesn't work, I'll try the other.

I'm sure everyone trying to repair any camera if not trained and specializing in the job, knows the risk of bricking it, as I did with my Canon compact, trying to open it to clean a sensor, and $700 later still regretting it
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
aperture, board, bottom, camera, force, frame, horse, k-30, k-50, magnet, pentax k30, pentax k50, photo, post, replacement, rick, screw, screws, shoe, solenoid, teflon, time, wires
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
K-30 / K-50 Aperture Block Failue - Repair Solution available Altglas Pentax K-30 & K-50 1050 12-03-2023 12:25 AM
K-30 Aperture control and battery problem mgvh Troubleshooting and Beginner Help 10 10-21-2016 06:56 AM
K-30/ K-50 Aperture DIY Repair richandfleur Repairs and Warranty Service 25 07-30-2016 03:13 PM
K-30 Aperture lever - Convert to IR, fix it , flog it, or bin it? Ian.morgan Repairs and Warranty Service 17 05-02-2016 09:27 AM



All times are GMT -7. The time now is 05:15 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top