[photogem]

Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here.

---

Solenoid-Replacement Pentax K-S2
(Pentax K-70 is almost identical except screw of solenoid situated on left instead of right side!)

Tools required:
- Soldering iron with pencil-tip: Ersa Multi-Pro 20W or soldering needle/USB soldering iron.
>>> Butan-gas soldering-iron = A absolute 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)
- Screwdrivers JIS000 or PH00 + PH000 (JIS size works for all screws, PH000 a must for the solenoid screw. JIS is preferable!)
- Tweezers or precision pliers
- Headlamp is very useful, makes things easier
- photos of the K-S2 with location of screws.


Preparation:
- Print out all those photos, glue them on some cardboard, drill 2mm holes where 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-S2, 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 a better 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:
- 11 x screws direct access (green arrows)
- 3 x behind the battery-door (blue arrows)

- Like with other Pentax DSLR, there is one screw deep within battery-case left side: DON'T take this one out!



2. Remove all 3 x screws from the left side (2 of them hidden behind the rubber grip):






3. Remove all 3 x screws from the right side (all 3 hidden behind the rubber grip):






4. Open the flash (battery is out!):
Remove the 2 x screws there underneath the pop-up-flash and the 2 x screws where next to where you fix the strap/belt:






5. Remove the 2 x screws behind the rubber-eye-cup:





6. Now you lift the TOP-PART 1 cm (with the open flash). This is very important because otherwise the front-part is more difficult to remove!



7. Set the AF-MF switch on MF (see photo #2 where it is yet on AF)! Check position again when you assemble it back!
Make sure you understand its position: When on AF, the screwdrive is out, when on MF, it is retreated inside this small hole of the stainless-steel bayonet!
Take the FRONT-PART OFF: It is a bit tight, you might have to lever a bit to release it but don't worry, this is normal!



8. Now you have access to the green solenoid:





9. Unsolder both leads and unscrew the screw on the right side (K-70 left side, only difference). Take the solenoid out.


10. Install the white-Japan-made Solenoid (the only correct solution, avoid filing/grinding/sanding!):





11. Make sure you tighten the screw, you might want to fix it with threat-locking-laquer or nail-varnish, but I never needed to do it!

12.Solder the two wires back to the pins (left=pink//right=lilac). Crucial to do a good job, hold the wires with tweezers and pull to make sure they really are well soldered!

13. Now bring the top-part (with flash) back into position for being able to test the solenoid.
You might want to fix it with 2 screws (right to the viewfinder and the on the right strapholder, so the buttons have a good contact!
CLOSE THE POP-UP-FLASH!
Insert the battery and plug on a lens.
Switch the camera ON, in Av-Mode wide open take a photo.
You can see if the solenoid actuates and the photo should be alright.
If all is alright, take the lens, battery and the 2 screws off again.

14. Lift the Top part again slightly

15. AF-MF-Switch alignement: The is crucial now:
- Outer part of AF-MF-switch on the front-housing on MF:


the same switch from the inner side of the housing, you can see the rod which needs to be aligned:




- The internal part (black plastic, white arrow left) has to be upwards...


.... so the screwdrive mechanism "retreats" into this tiny hole (white arrow right). This mentioned rod of the AF-MF switch connects with the internal part!
(you have checked this before and understood the principle well, remember!)

16. Assemble to front-part back on and then the top-part (w. flash)

17: Test AF-MF-Switch! If it doesn't work correctly, take the front-part off again and realign!

18. There is this small plastic ring on the microphone-socket, don't lose it:


When you come to the bottom-plate, make sure you haven't missed this small part, which sometimes comes off:


It slides just on and off easely and is there to protect the cables from the display:


On its place it looks like this:


and with the bottomplate back on place it looks like this:


19. Very early K-S2's had a copper-washer glued with the same red thread-locking-laquer as the solenoidscrew onto the bottom part. You can see it very clearly here on this white K-S2:

This washer was used to even out a tiny hight-difference which was solved more elegant in later versions of the K-S2 and the K-70 (same body):

20. The rest is clear now, all screws in the same order as you got them out.


21. Test the K-S2 again: All should be fine

I have not written here about the differences of the solenoids, you can read more about this important issue HERE

Good luck!


If you are interested in this very interesting history of the development of the solenoid in Pentax SLR and DSLR bodies, then read this post:
A little history about the development of solenoids in Pentax cameras

---

Last edited by MarkJerling; 05-12-2021 at 01:45 AM. Reason: Photogem added information.

[Vmax911]

Well done! Hopefully I will never have to do this, but these instructions are great if I do.

[tonyzoc]

Solenoid-Replacement Pentax K-S2(Pentax K-70 is almost identical exept screw of solenoid situated on left instead of right side!)

Tools required:
- Soldering iron with precision soldering-tip (such as Ersa Multi-Pro 20W)
- 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-S2 with location of screws


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-S2, 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!


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:
- 11 x screws direct access (green arrows)
- 3 x when the battery-door is opened (blue + yellow arrow)
- Like with other Pentax DSLR, there is one screw deep within battery-case left side: DON'T take this one out!



2. Remove all 3 x screws from the left side (2 of them hidden behind the rubber grip):


3. Remove all 3 x screws from the right side (all 3 hidden behind the rubber grip):


4. Open the flash (battery is out!):
Remove the 2 x screws there underneath the pop-up-flash and the 2 x screws where next to where you fix the strap/belt:


5. Remove the 2 x screws behind the rubber-eye-cup:


6. Now you lift the TOP-PART (with the open flash) about 1 cm. This is very important because otherwise the front-part is more difficult to remove!


7. Set the AF-M switch on AF! Check position again when you assemble it back!
Make sure you understand its position: When on AF, the screwdrive is out, when on M, it is retreated inside this small hole of the stainless-steel bayonet!
Take the FRONT-PART OFF: It is a bit tight, you might have to lever a bit to release it but don't worry, this is normal!

8. Now you have access to the green solenoid:



9. Unsolder both leads and unscrew the screw on the right side (K-70 left side, only difference). Take the solenoid out.

10. Install the white-Japan-made Solenoid (the only correct solution, avoid filing/grinding/sanding like hell! ):


11. Make sure you tighten the screw, you might want to fix it with threat-locking-laquer or nail-varnish, but I never needed to do it!

12.Solder the two wires back to the pins (left=pink//right=lilac). Crucial to do a good job, hold the wires with tweezers and pull to make sure they really are well soldered!


13. AF-M-Switch alignement: The is crucial now:

- Outer switch on the front-housing on AF!
- The inner part (black plastic) has to be downwards so the screwdrive mechanism "pokes out" of this tiny hole (you have checked this before and understood the principle well, remember!):



14. Assemble the front part back and then the top-part (with flash).


15. Test AF-S-Switch! If it doesn't work correctly, take the front-part off again and realign!


16. The rest is clear now, all screws in the same order as you got them out.

17. Test the K-S2 and all should be fine

I have not written here about the differences of the solenoids, you can find that all HERE

Good luck!

Thanks so much for this. I ordered my white solenoid and I have all the tools needed. I do have some experience repairing cameras but mostly mechanical ones like Exaktas. I'm competent removing screws and soldering so this should be an easy repair.

[photolady95]

I'm assuming most ABF cameras would be the same, right? I have a K-30 and K-50 that has yet to experience this problem, but if it happens, I have a K-x I've been holding onto because it has two white solenoids inside it.

Your tutorial will be helpful if I ever need to replace the solenoid in either of my cameras.


Thanks for posting this.

[BigMackCam]

Fantastic tutorial and documentation. Although I don't own any of the potentially-affected cameras, I've enjoyed reading your posts on the subject. Your willingness to share information is laudable. Thank you!

[photogem]

You are all welcome!

I'm assuming most ABF cameras would be the same, right? I have a K-30 and K-50 that has yet to experience this problem, but if it happens, I have a K-x I've been holding onto because it has two white solenoids inside it.
Your tutorial will be helpful if I ever need to replace the solenoid in either of my cameras.

I guess you mean ABS-C cameras? There where Nikons which used solenoids as well, I am not familiar with those.
The principle of aperture-control via a solenoid was invented by Pentax, they had a patent on this.
I wrote a little history about it . Pentax uses it in many but not all DSLR bodies, an advanced control-mechanism is used in the K7/5/3/1/KP: Instead of a solenoid its a stepper-motor. You can see it here:
RiceHigh's Pentax Blog: Disassemble a K-5
There are also photos of the backside, pretty similar to the mechanism in the other Pentax DSLR bodies with solenoid!

You know, I did write a tutorial for the K30/50/500 (all the same), it is HERE


@tony Z.:
It will be very easy for you, just take good care about the AF-M-switch.
Good that you ordered the white solenoid, the only true solution.

[photolady95]

You are all welcome!



You know, I did write a tutorial for the K30/50/500 (all the same), it is HERE .

I did not see that one with the photos. Thanks for the link.

[Penview52]

Can you post a photo of solenoid spare part and where to buy it. Response is appreciated.

[sergysergy]

I don't have any of those cameras but I bet it will be really useful to many PF members. Well done!

[photogem]

Can you post a photo of solenoid spare part and where to buy it. Response is appreciated.

That's the correct one:

The solenoid can be purchased HERE*
or you find it in defunct Pentax bodies starting with the first Pentax DSLR: The *ist D (and all other *ist and Samsung GX models)
the K100/110/200D, the K2000, Kx, Km: in all those are usually 2 white Japan solenoids (not so in EU, often just 1, the Europeans were guinea-pigs for the green Chinasolenoid starting with the K100D!). One Japan-Solenoid for sure in: K10D/20D (Samsung GX10/20).
*I have zero relation to this seller!

[Penview52]

That's the correct one:

The solenoid can be purchased HERE*
or you find it in defunct Pentax bodies starting with the first Pentax DSLR: The *ist D (and all other *ist and Samsung GX models)
the K100/110/200D, the K2000, Kx, Km: in all those are usually 2 white Japan solenoids (not so in EU, often just 1, the Europeans were guinea-pigs for the green Chinasolenoid starting with the K100D!). One Japan-Solenoid for sure in: K10D/20D (Samsung GX10/20).
*I have zero relation to this seller!

Got it, so there is no more production of this kind but can be taken from junk camera?
Thanks.

[reh321]

Got it, so there is no more production of this kind but can be taken from junk camera?
Thanks.

Apparently the providing company moved production from Japan to China, and changed materials used, without changing product numbers. So, there was no alert that the product had changed - but it 'aged' differently - and the original version is no longer available new.

[Walkingwolf]

Really, really appreciate all this information. I fear that my K-S2 may also be going this way as it has had a few dark images, but so far not in any continuing sequence- so maybe not?
We’ll see as time goes on.

[photogem]

Really, really appreciate all this information. I fear that my K-S2 may also be going this way as it has had a few dark images, but so far not in any continuing sequence- so maybe not?
We’ll see as time goes on.

As soon as it starts with the first few dark photos the solenoid will stick more and more.
With the K30/50/500 it was possible to use Eneloops which deliver more mA's (due to the characteristics of NiMH's compared to Li-Ion) but this wasn't always an infinite solution.

Best to prepare for what most possibly will happen and find the time for DIY.
It is pretty easy!

Anyway: If the solenoid is stuck again, by all means don't do serial shooting (which some sadly recommend):
This can bring the complex system into disorder, i.e. misalign it.
Alignment can be done but needs further knowledge, more complicated then just to exchange the solenoid.
Misalignement does also happen when sanding/filing

But many don't even notice it as much as they don't notice that exposure is wrong when taking photos via Liveview, because all solenoid based DSLR cameras measure exposure-time in Liveview-mode with f4 (except the K20D) but with stuck solenoid not f4 but full-closed aperture, such as f22 or whatever the max. f is for the given lens.

[Penview52]

photogem: ..." exposure is wrong when taking photos via Liveview" this is my sample to prove the phrase is correct that it resulted black image.

The following settings gives a dark photo - AF, ks2 - 18-50 mm, indoor not sufficient light with flash, Tav mode : F8, 1/500 sec., iso 3200, ev-.3 and f11, 1/700 sec.,iso 3200, ev-.3