[photogem]

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Solenoid-Replacement Pentax K-S1

Tools required:
- Soldering iron with precision soldering-tip (such as Ersa Multi-Pro 20W, no butan-gas soldering-pen: Too hot!)
- Screwdrivers JIS 000 or PH000 + PH00 (JIS size works for all screws, PH000 for solenoid screw. JIS is preferable!)
- Tweezers or precision pliers
- Headlamp is very useful, makes things easier
- photos of K-S1 with location of screws, you find them HERE


Preparation:
- Print out all those photos, glue them on some cardboard, drill 2mm holes were the screws are located so you can later on stick all those screws into those holes. Makes it easier and safe due to different length of the screws.
- Make sure you took the battery out 24 hours prior undertaking the repair. This is for discharging the flash-condenser, which is well protected within the K-S1, nevertheless you don't want to risk getting a nasty shock! This condenser charges as soon as you open the pop-up-flash with battery inside the switched-on camera! So don't open the flash prior removal of the battery! You need to open it for access of 3 screws!
- For another option how to discharge the flash-condenser read HERE

Sequence of opening the body (Body-cap is mounted on the K-mount for protection of sensor etc.)

1. Remove all screws from the bottom part: 6 x screws direct access, 2 x when the battery-door is opened: Careful: One of these screws holds a small metal plate which partly holds the right plastic side! Take this metal piece off with tweezers! There is another screw: 1 x deep within battery-case left side. The next photo shows this metal plate. Don't lose it!


2. Remove all 3 x screws from the left side (direct access)
3. Removal of screws right side: Open the HDMI/USB rubberdoor. Take off the HDMI/USB-sticker! Now you have access to the 2nd screw holding the plastic-side-piece. Unscrew it and take the plastic-side-piece off. Now you have access to 4 more screws, but you only need to unscrew the 2x front screws!

4. Removal of screws front: Take the rubber on the left side off. Now you have access to 3x screws, remove them.

Photo: Front rubber + HDMI-USB-sticker:



Photo: Hidden screw underneath HDMI-USB-Sticker:



Photo: Right plastic-side is removed: Red dots indicate the front screws which have to be removed:



Photo: Hidden screws underneath front rubber:



5. Take of the eye-piece: Unscrew the 2 x screws behind it.

6. Open the pop-up-flash (remember, no battery inside your camera!). Remove the 3 screws there plus the 2 screws next where the strap is fixed
7. Lift the top part with the flash about 1/2" inch. Don't lift it off completely! This is necessary to take of the front part and to slide it off.
The top part "hooks" into the frontpart!

8. AF/M-Switch on M! This has to be checked later on again!
9. Gently "pull off" the front part. There is a kind of nose which has to be lifted, here marked with red dots:




Now you have access to the solenoid.
Place the camera on some soft tissue as shown here:




Unsolder the solenoid. For this gently pull the wires forward, because they are fixed with some elastic glue to the left!


First unsolder the right purple wire:
Gently hold the wire with the tweezers while you touch the bare end soldered onto the solenoid until it comes off

Next 2 photos have been taken by a kind person not knowing about "DOF" and never had used my KP before... so when I noticed it this K-S1 was reassembled, it was too late. Anyway, these photos show you how easy it is to solder off the wires! Don't be scared!





Same for the left pink wire:



Photo: Solenoid with wires off:


Now you can unscrew the solenoid, the screw and right side of the solenoid is fixed with red thread-locking-lacquer which comes off easily.


You can see clearly were the solenoid is fixed to:
Left the nose and right the hole for the solenoid screw:



The lever for the plunger of the solenoid. It moves the shutter-mechanism:


Now solder a tiny amount of solder onto the bare ends of the pink and violet wire!

Screw the white "made in Japan" solenoid in.

Why this solenoid and no other one nor filing/sanding the faulty China-solenoid you can read about
HERE =Manual for solenoid-replacement Pentax K30/50/500

You might fix the screw and the left hole with some thread-locking-lacquer or nail-varnish:



Solder the wires back onto the solenoid. Make sure the solder holds well (Test by pulling the wires gently with the tweezers!):






Re-Assembling of the body:

- Check that the inner and outer part of the AF/M-Switch are on M:
The inner part is on M when the screw-drive gear in this small hole in the metal K-bajonett is retreated!

Now the part "which demands good patience":

- Gently plug-on the front part again. You can see on the linked photo why this is a bit fiddly: The ON/OFF switch has to fit as well as the AF/M-Switch! This "nose" which I mentioned for the disassembly part: Make sure you don't hurt the flat ribbon wire that sits at this very region this nose slides back onto the main body! Sounds complicated but "when you are there" it is easy to understand and follow. Also be careful: The inner part of the AF-M-switch has a tiny metal ball which stops at those 2 positions AF and M. Don't lose this ball (it actually sits there very tight, only rough treatment will get it lose!).

Remember to llift the top-part with the flash for this 1/2" again! Make sure the front sits well. Take your time, be patient. Don't push or force anything!

- Screw in the 3 screws which were hidden under the rubber. Fix the rubber to its place.

- Screw in the 2 screws in the right (grip) side. Fix the plastic-side-piece on the right side. Fix the small screw which was covered by the HDMI/USB strip!
Fix that one as well back on its place!

- Screw in the 3 screws for the left side and all 5 screws on the top!

- Fix the bottom part with all screws plus the small metal piece

- Insert the battery, an AF Lens and take a test photo with AV, TV or TAV and large or open aperture such as f2,8. All should be fine.

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Last edited by photogem; 12-15-2019 at 10:12 PM.

[marcusBMG]

Great job producing that photogem - thanks.
Might be good to put in the pentax articles > diy section too.

[peteedee]

Can you tell me where to buy the White Solenoid? Thank you.

[photogem]

On ebay.com (be careful, lots of China-made green ones there as well, and many of them not even the originals but cheaper made)

Pentax K-30 K-50 K-S1/S2 K-500 Genuine White Aperture Solenoid Part - Japan - | eBay

[italchux]

Thanks for this very detailed and precise "How to" DIY.
I have been dreading any suggestion of opening the camera, guess I have no choice now.
Thanks

[photogem]

It's pretty straight forward and actually very easy. The main hinterance usually is one's own fear!
Once it's shouldered, it's light!

[reh321]

Thanks for this very detailed and precise "How to" DIY.
I have been dreading any suggestion of opening the camera, guess I have no choice now.
Thanks

Everyone does have a choice.
Fix the camera as explained here, use the camera as is (*), or purchase a replacement.

(*) The author and I have discussed this, and even if he were available right now, I would not pursue it further, but the only thing broken in these cameras is body's ability to control aperture. Use the body with lenses equipped with aperture rings so aperture can be controlled by lens, then use green-button metering and camera can take good images again. That is what I did with my K-30, and I personally don't find it to be at all tiresome.

[photogem]

The problem of member italchux is not the solenoid but a stuck motordrive on his K-S2. He cannot switch back into MF-Mode but the screwdrivemechanism always pokes out of the small hole in the K-bajonet. He cannot do any manual focusing, it is blocked. So opening his body might be the only choice although I guess there is something more serious jammed, not just the switch.

@italchus:
For you better study the repair manual of the K-S2:
https://www.pentaxforums.com/forums/184-pentax-k-s1-k-s2/399162-manual-solen...s2-k-70-a.html

[dballare]

Hello fellow Pentax users.

I've been reading the threads regarding solenoid replacement on K-30, K-50 etc. My daughter has a K-50 with the typical problem of dark images. Being an electrical engineer and familiar with soldering techniques, I thought I might try fixing my daughter's camera.


I've read the quite extensive threads on this repair and I'm impressed with the detail and cautionary notes. However, I have not been able to find any note on where one might obtain the necessary white solenoid for replacement. Does this simply involve contacting the Pentax tech support?

Thanks,

Dan.

[photogem]

Either on ebay
or in old (ideal for parts only) Pentax bodies as mentioned here

This is the thread for the K-S1 though!

[peteedee]

Pentax K-30 K-50 K-70 K-S1/S2 K-500 Genuine White Solenoid Part - Japan - | eBay

[Marktax]

Thank you for a Great presentation. For interest, I fixed my K-S2 by filing the plunger in the green solenoid. I did not replace it with the white solenoid. I have shot thousands of pictures since with no problems whatsoever. Maybe one day it will fail again, but so far so good. I believe I know the trick to filing the plunger successfully.

On another note, on my camera the black wire that connects to the lens mount ring directly above the solenoid either was not connected when I open the camera, or I accidentally pulled it loose during disassembly. I did not notice pulling it loose, so I suspect it had come undone at some earlier time, through a weak connection from the factory. In any case, I did not have a precision soldering tool, so I was unable to reconnect the black wire. The wire is extremely short, with no slack, and with no room at the end to strip and make a good solder anyway. Even with a precision soldering tool, I don't think I could've reconnected that wire. Nevertheless, I have noticed no ill effects at all from leaving that wire unconnected. Thousands of pictures later, perhaps more clicks then I had taken before the solenoid failed initially, my K-S2 is operating fine.

[photogem]

You told me this before here:
Confirming troublesome stop down metering behavior - PentaxForums.com
So I don't understand why you have to repeat this in the K-S1 Tutorial thread, this doesn't make sense at all!

So many times that I have explained why I insist to stay away from sanding/filing and in the meantime I had several (well) filed solenoids in my hands which failed again.

There is a German official repairshop which does it the most advanced way and maybe takes the least risk of rust on the treated (filed in your case) surface and yet some of them failed just shortly after the warranty of 1 yr. was over.

The California Repairshop "PC35 Photolab" sands/files as well and we had a few complaints that it went wrong again.
HERE you can study well why it went wrong.



For official repairshops I do understand this approach, they cannot insert a used white Japan solenoid!

But those of us who have the chance to either search for an early Pentax DSLR damaged body which has the Japan solenoid (or two) or to buy one on ebay.com...

... it is as I often said: Why use bad oil in for your car's engine when there is good oil?

And there have been cases were the complete mechanism went out of alignement needing then very complex adjustment.
And I know of at least 2 cases when it then developed into complete failure: Only possibility to replace the whole diaphragm-control-block which is hours of very complex work. Not recommended.

I know that there are cases when filing did work, but I don't recommend it at all and this here is a tutorial of how to do it right and not of how to what I call "cheat". Of course not cheating others (exept one sells the body and does not mention it!) but in the sense when one takes on a diet and then cheats.

Even if very well filed the other negatives of the green solenoid won't go away, they stay!
So one acts kind of mean towards oneself and one's (great) camera imo.

About the black wire: This is an ground-wire! It connects some part to the main ground (chassis stainless steel) so if some part does discharge, no damage can happen.

So nothing might happen but it can happen.

The wire is short for a reason because it is near the solenoid and could otherwise get in its way.

It is soldered and if it brakes off, it is then too short and has to be made longer by adding an thin wire the correct way (insulated of course, if just made longer then with very thin heatshrinking-tube).

I daubt it came off by itself: Unscrewing the green solenoid and pulling it out with its two wires still connected would much more likely be the reason because this is more of a fiddly and critical job than just soldering the wires of.
And then one does not file but insert the good Japan solenoid.


You see, if one has the white Japan solenoid tight in ones hands and compares it (also if filed) with the green China version one does understand why the Japan solenoid is way superior.

Also, Ricoh has done mods to the green solenoid and they have less failure but yet some do fail and when I compare the modified solenoid manufactured post 12/2015, it is for sure better made but yet PET remains PET and does not by magic turn into the superior PTFE. This material is one of the reasons why the Japan solenoid never ever failed!

[photogem]

More details about solder and soldering iron:

- Soldering iron with pencil-tip: Ersa Multi-Pro 20W or soldering needle/USB soldering iron. Butan-gas s.iron = No-Go! Too hot, it will do damage!
- Solder: Good quality thin resin flux solder (I use thin leaded solder, for such a small work it is not really dangerous due to its lead-content)

[c.kampfraath]

Solenoid-Replacement Pentax K-S1

Tools required:
- Soldering iron with precision soldering-tip (such as Ersa Multi-Pro 20W, no butan-gas soldering-pen: Too hot!)
- Screwdrivers JIS 000 or PH000 + PH00 (JIS size works for all screws, PH000 for solenoid screw. JIS is preferable!)
- Tweezers or precision pliers
- Headlamp is very useful, makes things easier
- photos of K-S1 with location of screws, you find them HERE


Preparation:
- Print out all those photos, glue them on some cardboard, drill 2mm holes were the screws are located so you can later on stick all those screws into those holes. Makes it easier and safe due to different length of the screws.
- Make sure you took the battery out 24 hours prior undertaking the repair. This is for discharging the flash-condenser, which is well protected within the K-S1, nevertheless you don't want to risk getting a nasty shock! This condenser charges as soon as you open the pop-up-flash with battery inside the switched-on camera! So don't open the flash prior removal of the battery! You need to open it for access of 3 screws!
- For another option how to discharge the flash-condenser read HERE

Sequence of opening the body (Body-cap is mounted on the K-mount for protection of sensor etc.)

1. Remove all screws from the bottom part: 6 x screws direct access, 2 x when the battery-door is opened: Careful: One of these screws holds a small metal plate which partly holds the right plastic side! Take this metal piece off with tweezers! There is another screw: 1 x deep within battery-case left side. The next photo shows this metal plate. Don't lose it!


2. Remove all 3 x screws from the left side (direct access)
3. Removal of screws right side: Open the HDMI/USB rubberdoor. Take off the HDMI/USB-sticker! Now you have access to the 2nd screw holding the plastic-side-piece. Unscrew it and take the plastic-side-piece off. Now you have access to 4 more screws, but you only need to unscrew the 2x front screws!

4. Removal of screws front: Take the rubber on the left side off. Now you have access to 3x screws, remove them.

Photo: Front rubber + HDMI-USB-sticker:



Photo: Hidden screw underneath HDMI-USB-Sticker:



Photo: Right plastic-side is removed: Red dots indicate the front screws which have to be removed:



Photo: Hidden screws underneath front rubber:



5. Take of the eye-piece: Unscrew the 2 x screws behind it.

6. Open the pop-up-flash (remember, no battery inside your camera!). Remove the 3 screws there plus the 2 screws next where the strap is fixed
7. Lift the top part with the flash about 1/2" inch. Don't lift it off completely! This is necessary to take of the front part and to slide it off.
The top part "hooks" into the frontpart!

8. AF/M-Switch on M! This has to be checked later on again!
9. Gently "pull off" the front part. There is a kind of nose which has to be lifted, here marked with red dots:




Now you have access to the solenoid.
Place the camera on some soft tissue as shown here:




Unsolder the solenoid. For this gently pull the wires forward, because they are fixed with some elastic glue to the left!


First unsolder the right purple wire:
Gently hold the wire with the tweezers while you touch the bare end soldered onto the solenoid until it comes off

Next 2 photos have been taken by a kind person not knowing about "DOF" and never had used my KP before... so when I noticed it this K-S1 was reassembled, it was too late. Anyway, these photos show you how easy it is to solder off the wires! Don't be scared!





Same for the left pink wire:



Photo: Solenoid with wires off:


Now you can unscrew the solenoid, the screw and right side of the solenoid is fixed with red thread-locking-lacquer which comes off easily.


You can see clearly were the solenoid is fixed to:
Left the nose and right the hole for the solenoid screw:



The lever for the plunger of the solenoid. It moves the shutter-mechanism:


Now solder a tiny amount of solder onto the bare ends of the pink and violet wire!

Screw the white "made in Japan" solenoid in.

Why this solenoid and no other one nor filing/sanding the faulty China-solenoid you can read about
HERE =Manual for solenoid-replacement Pentax K30/50/500

You might fix the screw and the left hole with some thread-locking-lacquer or nail-varnish:



Solder the wires back onto the solenoid. Make sure the solder holds well (Test by pulling the wires gently with the tweezers!):






Re-Assembling of the body:

- Check that the inner and outer part of the AF/M-Switch are on M:
The inner part is on M when the screw-drive gear in this small hole in the metal K-bajonett is retreated!

Now the part "which demands good patience":

- Gently plug-on the front part again. You can see on the linked photo why this is a bit fiddly: The ON/OFF switch has to fit as well as the AF/M-Switch! This "nose" which I mentioned for the disassembly part: Make sure you don't hurt the flat ribbon wire that sits at this very region this nose slides back onto the main body! Sounds complicated but "when you are there" it is easy to understand and follow. Also be careful: The inner part of the AF-M-switch has a tiny metal ball which stops at those 2 positions AF and M. Don't lose this ball (it actually sits there very tight, only rough treatment will get it lose!).

Remember to llift the top-part with the flash for this 1/2" again! Make sure the front sits well. Take your time, be patient. Don't push or force anything!

- Screw in the 3 screws which were hidden under the rubber. Fix the rubber to its place.

- Screw in the 2 screws in the right (grip) side. Fix the plastic-side-piece on the right side. Fix the small screw which was covered by the HDMI/USB strip!
Fix that one as well back on its place!

- Screw in the 3 screws for the left side and all 5 screws on the top!

- Fix the bottom part with all screws plus the small metal piece

- Insert the battery, an AF Lens and take a test photo with AV, TV or TAV and large or open aperture such as f2,8. All should be fine.

This manual saved a second-hand K-S1, a rare camera in the Netherlands
Thanks!