[photogem]

Congratulations! Well done!

Soldering might be best tried out on some other parts, such as taking the insulation of two thin wires of and soldnering them together and then desolder them.
The most important part is a good small tip such as the shape of a pencil. Even a soldering-needle will do if one has a 12V powersupply which is strong enough.
There are even USB soldering-irons and soldering-needles.

The most imporant part is to have the hand which holds the soldering-iron resting well on the grip-side of the camera.
Then everthing is quiet/motionless enough, the other hand holds the wire for de- and soldering.

[Mcgutierre]

Thanks! I soldered keeping the solenoid as far from the camera as the lenght of the cables let me, so the tip keep away from the plastic parts of the camera. I held the solenoid using a metal clamp so I could hold cable an soldering tool with both hands. Anyway it was really stressing, but now I'm very happy!!

[doc_taz_nj]

Grateful that you posted this. Already have this saved as a pdf and printed out to a binder with a couple of older Pentax film camera manuals (K1000 and *ist <--- this one is EPIC for an entry level SLR, for good reasons).

Thanks!

[photogem]

Thanks! I soldered keeping the solenoid as far from the camera as the lenght of the cables let me, so the tip keep away from the plastic parts of the camera. I held the solenoid using a metal clamp so I could hold cable an soldering tool with both hands. Anyway it was really stressing, but now I'm very happy!!

Maybe I misunderstood so correct me if I am wrong:

Did you first solder the wires to the not yet built in solenoid?

If so, this would be very fiddly.

- One first installs the solenoid with the screw so it sits tight.
- Then one has one hand to hold the solenoid with pliers (I use the great Xuron 450 nosepliers which are the best I ever came across.
- The other hand holds the precison soldering-iron with pencil-tip and I am thinking of buying this one

---------- Post added 02-25-20 at 11:16 PM ----------

Grateful that you posted this. Already have this saved as a pdf and printed out to a binder with a couple of older Pentax film camera manuals (K1000 and *ist <--- this one is EPIC for an entry level SLR, for good reasons).

Thanks!

Yes, the *ist is for several reasons a nice backup camera, I still like it, particular the old DS and the DS2.
One can install the green solenoid into the flash compartment without any risk and use it's white solenoid from there for the modern K-body such as the K-70!

Can anybody explain why these two responses written shortly one after each other are displayed like this one as one post?
Happened before but I would prefer those to be two completly different posts!

[pdr]

Hello,
Having dark frames with my K70 i decided the "do it yourself" fix following this tutorial. I have a white solenoid taken from my k10d but i was pretty worried about the soldering. So i pulled off the plunger and compared it to the one found in k70. Although seemingly identical at size, under strong light i noticed that the edges (the feet) of the one taken from k10d were significantly thinner. So i replaced only the plunger...no need for soldering. Everything is just ok since. No dark frames at all. Hope it lasts

[photogem]

Having dark frames with my K70 i decided the "do it yourself" fix following this tutorial. I have a white solenoid taken from my k10d but i was pretty worried about the soldering. So i pulled off the plunger and compared it to the one found in k70. Although seemingly identical at size, under strong light i noticed that the edges (the feet) of the one taken from k10d were significantly thinner. So i replaced only the plunger...no need for soldering. Everything is just ok since. No dark frames at all. Hope it lasts

Well, you were already there.


Actually unscrewing the solenoid and changing the plunger is as much fine work as is the soldering.
But you need a fine soldering tip.

Removing the backup battery is far more difficult, unsoldering the wires of the solenoid peanuts compared to that!

Well, it works for now.


BUT:
Even when just taking out the plunger and putting it back it works for a while!
But then the problem returns always returns.

We will see but I don't recommend half baked solutions, usually they bring further difficulties.

[Mcgutierre]

Maybe I misunderstood so correct me if I am wrong:

Did you first solder the wires to the not yet built in solenoid?

If so, this would be very fiddly

You are right, I chose that way because I was afraid of touching any plastic part of the camera.

[pdr]

If it goes bad again i 'll report. Anyway, thanks a lot for the tutorial. Had i not read it, i 'd be still keep on getting angry by pushing again and again the preview button to make my camera work. Only two years old, while k10d has never had a problem for 14 years...

[photogem]

The white Japan-Solenoid as you have it in your K10D has never failed!
It lasts and lasts and lasts.

[ShawnH]

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

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-70 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-70, 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:
- 11 x screws direct access (green arrows)
- 3 x behind the battery-door (red 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 (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-MF switch on MF (see photo #2 but there it is on AF)! Check position again when you assemble it back!
Make sure you understand its position: When on MF, the screwdrive is in/retreated, when on AF, it comes out of 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 LEFT SIDE (K-S2 has it on the right side, otherwise everything is the same). 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. AF-MF-Switch alignement: The is crucial now:
- Outer part of AF-MF-switch on the front-housing on MF:




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

.... so the screwdrive mechanism "retreats" into this tiny hole (white arrow right). The rod of the AF-MF switch connects with the internal part!
(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-MF-Switch again! If it doesn't work correctly, take the front-part off again and realign!


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


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


18. Test the K-70 and all should be fine

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

Where do I get a white Japanese Solenoid replacement?

---------- Post added 03-17-20 at 03:08 PM ----------

Where do I get a white Japanese Solenoid replacement?

[photogem]

on ebay com:
search for genuine white solenoid
For Germans on ebay Kleinanzeigen as well.
Bordercountries as well as long trade functions, because boarders are closed due to the crisis

[amg2000]

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

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-70 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-70, 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:
- 11 x screws direct access (green arrows)
- 3 x behind the battery-door (red 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 (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-MF switch on MF (see photo #2 but there it is on AF)! Check position again when you assemble it back!
Make sure you understand its position: When on MF, the screwdrive is in/retreated, when on AF, it comes out of 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 LEFT SIDE (K-S2 has it on the right side, otherwise everything is the same). 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. AF-MF-Switch alignement: The is crucial now:
- Outer part of AF-MF-switch on the front-housing on MF:




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

.... so the screwdrive mechanism "retreats" into this tiny hole (white arrow right). The rod of the AF-MF switch connects with the internal part!
(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-MF-Switch again! If it doesn't work correctly, take the front-part off again and realign!


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


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


18. Test the K-70 and all should be fine

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

Thanks for the clear instructions! I bought a new K70 in November 2017 and have been seeing signs of the aperture problem. So far it only seems to happen when the camera has bee turned off, the first exposure after I turn on the camera is either way underexposed if I'm using the optical viewfinder, or way overexposed if I'm using live view. After the first exposure it seems to be fine. I'm going to wait until the problem gets worse before I attempt this. I own both a K-10 with a damaged sensor, I can get the white solenoid from there.
Of course I bought this camera because I owned a K50 and wanted a backup (actually the K50 became the backup, and so far doesn't seem to have the aperture problem.) Kind of ironic that I was worried about my K50 getting the problem, and the K70 ends up with the problem.

[photogem]

Thanks for the clear instructions! I bought a new K70 in November 2017 and have been seeing signs of the aperture problem. So far it only seems to happen when the camera has bee turned off, the first exposure after I turn on the camera is either way underexposed if I'm using the optical viewfinder, or way overexposed if I'm using live view. After the first exposure it seems to be fine. I'm going to wait until the problem gets worse before I attempt this. I own both a K-10 with a damaged sensor, I can get the white solenoid from there.
Of course I bought this camera because I owned a K50 and wanted a backup (actually the K50 became the backup, and so far doesn't seem to have the aperture problem.) Kind of ironic that I was worried about my K50 getting the problem, and the K70 ends up with the problem.

Check via this method, and do it right away after your K-70 wasn't in use for a few days, because it is typical for the problem arising after a period when the camera was not used:
How to detect aperture-block failure/stuck solenoid on Pentax K-70 - PentaxForums.com

Do first the check via Live-View because it is very obvious to see the fully closed aperture instead of f4,0!
But don't release, switch LV off and then via OVF (opt. view-finder) take a photo in AV or TAV full open such as f1,8 with the DA50

My experience with the K30/50/500/K-S1/S2 is, that LV does work for a while and gives alright exposures (but not perfect!)
while you are the 4.th person I know of having overexposed photos with the K70 in LV-mode with stuck solenoid.

Now, also take into account:
The longer one runs a car with a fault in the engine, the higher the risk of further damage.
It isn't that dramatic with those Pentax bodies and stuck solenoid but it did happen.
Also you might be frustrated if the problem occurs just then when you have a good photo-session.

So you have the solenoid almost ready, now we have days of curfew, so a good time to meet that challenge?

[amg2000]

Check via this method, and do it right away after your K-70 wasn't in use for a few days, because it is typical for the problem arising after a period when the camera was not used:
How to detect aperture-block failure/stuck solenoid on Pentax K-70 - PentaxForums.com

Do first the check via Live-View because it is very obvious to see the fully closed aperture instead of f4,0!
But don't release, switch LV off and then via OVF (opt. view-finder) take a photo in AV or TAV full open such as f1,8 with the DA50

My experience with the K30/50/500/K-S1/S2 is, that LV does work for a while and gives alright exposures (but not perfect!)
while you are the 4.th person I know of having overexposed photos with the K70 in LV-mode with stuck solenoid.

Now, also take into account:
The longer one runs a car with a fault in the engine, the higher the risk of further damage.
It isn't that dramatic with those Pentax bodies and stuck solenoid but it did happen.
Also you might be frustrated if the problem occurs just then when you have a good photo-session.

So you have the solenoid almost ready, now we have days of curfew, so a good time to meet that challenge?

Thanks. I'm going to need to get a soldering iron with a fine tip first. I think our local Home Depot is considered an essential business. And it's right next door to our supermarket, where we're going to have to go some time this week.

[amg2000]

Check via this method, and do it right away after your K-70 wasn't in use for a few days, because it is typical for the problem arising after a period when the camera was not used:
How to detect aperture-block failure/stuck solenoid on Pentax K-70 - PentaxForums.com

Do first the check via Live-View because it is very obvious to see the fully closed aperture instead of f4,0!
But don't release, switch LV off and then via OVF (opt. view-finder) take a photo in AV or TAV full open such as f1,8 with the DA50

My experience with the K30/50/500/K-S1/S2 is, that LV does work for a while and gives alright exposures (but not perfect!)
while you are the 4.th person I know of having overexposed photos with the K70 in LV-mode with stuck solenoid.

Now, also take into account:
The longer one runs a car with a fault in the engine, the higher the risk of further damage.
It isn't that dramatic with those Pentax bodies and stuck solenoid but it did happen.
Also you might be frustrated if the problem occurs just then when you have a good photo-session.

So you have the solenoid almost ready, now we have days of curfew, so a good time to meet that challenge?

I'm curious how opening up the camera impacts it's weather sealing? I've always been careful even with the weathersealing. Obviously repaired camera with compromised weather sealing is better than a fully weather sealed camera that's not totally functional. Just wondering if anyone has any experience with that. Common sense tells me once I've opened the camera I'd need to be extra cautious about moisture going forward.