[photogem]

All I asked was if somebody who have changed to white solenoid experienced failure even with the white solenoid. This will narrow down to the cheap solenoid that Ricoh uses on the cheaper camera bodies, if not then there is something else not right with the whole design.

No you didn't! (English is not my native language

You wrote:
"Anybody with the white replacement that has failed too?"

The last word "too" implies that *YOU* (or another person who mentioned it!) has experienced failure with the white solenoid!

Which is not the case. Nobody had problems with the white solenoid.*

This thread is there to help people to solve their problem with a faulty solenoid and not to confuse them further.

You have exchanged now 1 solenoid which is fine and you wrote about it here posting #83 .

You describe well all the errors that can be done if one is not precise, patient and... prepared ... or... doesn't know about what to be prepared for, such as the AF switch which has to be positioned in the right way.
*but you see, all those mistakes and more could lead to further damage.

All this is fine, but your experience is yet just 1 solenoid exchange (which is 1000 x more compared to those who haven't done so but write already books about it) But you have a little bit this tendency of an over-enthusiasm.... such as in your review of the SMC F35-70. You own it for 1 day and right away you write a review and rave about it with 9 points. 10 days later you downgrade it to a 7, few month later you revise your 2.nd opinion and upgrade it to 9 again. I find this confusing, some patience might be useful here?

There are some who haven't even encountered 1 single exchange of a solenoid but they debate endlessly what could and couldn't be the fault. You have made the effort and you don't shy away of telling about all the encountered mistakes, which I find great!

So all this is about a little more presicion, because as another member wrote:

Hello,
I've been reading this thread from end to end (which has taken days)

To avoid that it takes people even longer than those days, one should keep the information in this threat precise and... based on some experience.

What I mean are commenaries such as:

... if not then there is something else not right with the whole design

Because there is actually zero logic behind it but only guessing. There is no "something else not right with the whole design".
This design worked well until the Kx. The Kr was a very bad design, it quickly disappeared, the way the shuttermechanism was designed there lead to many having to fail, even with low actuations. They repaired this with the K30 but already in many K100D, K200D and Kr/Kx they used the green solenoid in the flash compartment (actually 90% of all those I had opened and I was the first person to open them for sure). Pentax and Ricoh did just trust that this part would be fine, because it came from the same Japanese manufacturer who changed production from Japan to China and Taiwan
(I have verified this!). I was able to purchase some NOS (new old stock) made in Japan solenoids as well as NOS green made in China/Taiwan versions. I one really studies them in detail, the difference is quite striking, the MIJ versions are way way superior. It is the difference of a Japanese forged knive compared to a cheap made in China knive. The chinese knive might have a chrome-plated surface to even shine more, but after a few minutes use in the kitchen you know about it. I guess Pentax/Ricoh had no idea about it. There was no reason for this. On the surface they just have a different colour.



---------- Post added 02-12-18 at 04:34 AM ----------

Finally it works. The green solenoid is replaced by the white one from an old MZ50. I check both of them and realize that the green one needs more force to take the horse shoe apart. The DC resistance of the green is 30 Ohms, same as the white. When it is in circuit of K50, It is also 30 Ohms in both forward and reverse probes, not decreased or increased by shunt/series circuit if any.

I don't understand what you mean with "forward and reverse probes" and "decrease/increase by shunt/series circuitry" ???

I am asking because here my English lacks.

I have changed polarity on the solenoid for a short moment. This leads to an even stronger holding force, the power of the tiny magnet then is
enhanced (which is logical).

Somebody once encountered this problem of a stronger holding force in a German forum.
He wrote that polarity could be changed via turning the magnet and this solved the problem.
I came across twice to white MIJ solenoids with reversed polarity. Changing the cables is the (only) solution.

[slartibartfast01]

No you didn't! (English is not my native language

You wrote:
"Anybody with the white replacement that has failed too?"

The last word "too" implies that *YOU* (or another person who mentioned it!) has experienced failure with the white solenoid!

Which is not the case. Nobody had problems with the white solenoid.*

This thread is there to help people to solve their problem with a faulty solenoid and not to confuse them further.

You have exchanged now 1 solenoid which is fine and you wrote about it here posting #83 .

You describe well all the errors that can be done if one is not precise, patient and... prepared ... or... doesn't know about what to be prepared for, such as the AF switch which has to be positioned in the right way.
*but you see, all those mistakes and more could lead to further damage.

All this is fine, but your experience is yet just 1 solenoid exchange (which is 1000 x more compared to those who haven't done so but write already books about it) But you have a little bit this tendency of an over-enthusiasm.... such as in your review of the SMC F35-70. You own it for 1 day and right away you write a review and rave about it with 9 points. 10 days later you downgrade it to a 7, few month later you revise your 2.nd opinion and upgrade it to 9 again. I find this confusing, some patience might be useful here?

There are some who haven't even encountered 1 single exchange of a solenoid but they debate endlessly what could and couldn't be the fault. You have made the effort and you don't shy away of telling about all the encountered mistakes, which I find great!

So all this is about a little more presicion, because as another member wrote:


To avoid that it takes people even longer than those days, one should keep the information in this threat precise and... based on some experience.

What I mean are commenaries such as:

... if not then there is something else not right with the whole design

Because there is actually zero logic behind it but only guessing. There is no "something else not right with the whole design".
This design worked well until the Kx. The Kr was a very bad design, it quickly disappeared, the way the shuttermechanism was designed there lead to many having to fail, even with low actuations. They repaired this with the K30 but already in many K100D, K200D and Kr/Kx they used the green solenoid in the flash compartment (actually 90% of all those I had opened and I was the first person to open them for sure). Pentax and Ricoh did just trust that this part would be fine, because it came from the same Japanese manufacturer who changed production from Japan to China and Taiwan
(I have verified this!). I was able to purchase some NOS (new old stock) made in Japan solenoids as well as NOS green made in China/Taiwan versions. I one really studies them in detail, the difference is quite striking, the MIJ versions are way way superior. It is the difference of a Japanese forged knive compared to a cheap made in China knive. The chinese knive might have a chrome-plated surface to even shine more, but after a few minutes use in the kitchen you know about it. I guess Pentax/Ricoh had no idea about it. There was no reason for this. On the surface they just have a different colour.



---------- Post added 02-12-18 at 04:34 AM ----------



I don't understand what you mean with "forward and reverse probes" and "decrease/increase by shunt/series circuitry" ???

I am asking because here my English lacks.

I have changed polarity on the solenoid for a short moment. This leads to an even stronger holding force, the power of the tiny magnet then is
enhanced (which is logical).

Somebody once encountered this problem of a stronger holding force in a German forum.
He wrote that polarity could be changed via turning the magnet and this solved the problem.
I came across twice to white MIJ solenoids with reversed polarity. Changing the cables is the (only) solution.

In his post he said

"I have replaced the green solenoid with white on my K50, so far it's doing good. But back of the mind, how long it's going to last?

Anybody with the white replacement that have failed too?"

So from that it can be understood that his white solenoid has not failed and that "too" means "as well as" the green solenoid.

[lehoward]

Sorry that some electronic terms made you confused. It simply means that I have measured the coil when it is already soldered on board by using the probes of an ohmmeter. The measurement is made twice where in the second measurement I reverse the polarity of the probes. The purpose is to find if a device is shunted with the coil or not. I am trying to know the solenoid driver to see whether it can handle a 15 Ohms solenoid with double current. If it can then we have an option to safety use the “white” taken from CD/DVD box.

[suraswami]

No you didn't! (English is not my native language

You wrote:
"Anybody with the white replacement that has failed too?"

The last word "too" implies that *YOU* (or another person who mentioned it!) has experienced failure with the white solenoid!

Which is not the case. Nobody had problems with the white solenoid.*

This thread is there to help people to solve their problem with a faulty solenoid and not to confuse them further.

You have exchanged now 1 solenoid which is fine and you wrote about it here posting #83 .

You describe well all the errors that can be done if one is not precise, patient and... prepared ... or... doesn't know about what to be prepared for, such as the AF switch which has to be positioned in the right way.
*but you see, all those mistakes and more could lead to further damage.

All this is fine, but your experience is yet just 1 solenoid exchange (which is 1000 x more compared to those who haven't done so but write already books about it) But you have a little bit this tendency of an over-enthusiasm.... such as in your review of the SMC F35-70. You own it for 1 day and right away you write a review and rave about it with 9 points. 10 days later you downgrade it to a 7, few month later you revise your 2.nd opinion and upgrade it to 9 again. I find this confusing, some patience might be useful here?

There are some who haven't even encountered 1 single exchange of a solenoid but they debate endlessly what could and couldn't be the fault. You have made the effort and you don't shy away of telling about all the encountered mistakes, which I find great!

So all this is about a little more presicion, because as another member wrote:


To avoid that it takes people even longer than those days, one should keep the information in this threat precise and... based on some experience.

What I mean are commenaries such as:

... if not then there is something else not right with the whole design

Because there is actually zero logic behind it but only guessing. There is no "something else not right with the whole design".
This design worked well until the Kx. The Kr was a very bad design, it quickly disappeared, the way the shuttermechanism was designed there lead to many having to fail, even with low actuations. They repaired this with the K30 but already in many K100D, K200D and Kr/Kx they used the green solenoid in the flash compartment (actually 90% of all those I had opened and I was the first person to open them for sure). Pentax and Ricoh did just trust that this part would be fine, because it came from the same Japanese manufacturer who changed production from Japan to China and Taiwan
(I have verified this!). I was able to purchase some NOS (new old stock) made in Japan solenoids as well as NOS green made in China/Taiwan versions. I one really studies them in detail, the difference is quite striking, the MIJ versions are way way superior. It is the difference of a Japanese forged knive compared to a cheap made in China knive. The chinese knive might have a chrome-plated surface to even shine more, but after a few minutes use in the kitchen you know about it. I guess Pentax/Ricoh had no idea about it. There was no reason for this. On the surface they just have a different colour.



---------- Post added 02-12-18 at 04:34 AM ----------



I don't understand what you mean with "forward and reverse probes" and "decrease/increase by shunt/series circuitry" ???

I am asking because here my English lacks.

I have changed polarity on the solenoid for a short moment. This leads to an even stronger holding force, the power of the tiny magnet then is
enhanced (which is logical).

Somebody once encountered this problem of a stronger holding force in a German forum.
He wrote that polarity could be changed via turning the magnet and this solved the problem.
I came across twice to white MIJ solenoids with reversed polarity. Changing the cables is the (only) solution.

Dude, this is a Forum!! Not a Scientific thesis submission portal.

Definition of “forum” - English Dictionary

In UK English - Forum -

a situation or meeting in which people can talk about a problem or matter especially of public interest: a forum for debate/discussion


In American English - Forum -
an occasion or a place for talking about a matter of public interest:
The university sponsored a forum on affirmative action.

Business English - Forum -
a meeting in which people can discuss subjects that are important to them with others: create/provide a forum for sth The meeting provided a valuable forum for discussing the issue from many diverse perspectives.
an international/regional/public forum They plan to discuss the survey results in a public forum.
an economic/policy forum At its summer policy forum, Labour appears to have offered a compromise.
​ a group of people who use the internet to discuss subjects that are important or interesting to them:
an internet/intranet/online forum She's a regular blogger on an online forum.



Proof:
https://dictionary.cambridge.org/us/dictionary/english/forum

You want to pick on me, go ahead.

There are lot of people who post initial impression and later change based on what they experience.

I am not doing or running any scientific lab/experiments.

I am not forcing you to read my thoughts or views, more than welcome to move on and bug something else.

I enjoy my beloved Pentax and pictures it can take. I want them to last a long time.

---

Last edited by suraswami; 02-12-2018 at 06:46 PM.

[MarkJerling]

A friendly reminder to some recent posters to not get personal. I think there are lots of informative contributions here and I really don't want to have to slip on my moderator hat.

[photogem]

Sorry that some electronic terms made you confused. It simply means that I have measured the coil when it is already soldered on board by using the probes of an ohmmeter. The measurement is made twice where in the second measurement I reverse the polarity of the probes. The purpose is to find if a device is shunted with the coil or not. I am trying to know the solenoid driver to see whether it can handle a 15 Ohms solenoid with double current. If it can then we have an option to safety use the “white” taken from CD/DVD box.

I have twice tried to install a 15 ohms solenoid into the K30. It didn't work.
I also tried to install it into the flash-open circuitry of a K x which didn't work either.

I came across some NOS blue 15 ohms and green 30 ohms solenoids but it was a waste of money.

[bigyinn]

I have twice tried to install a 15 ohms solenoid into the K30. It didn't work.
I also tried to install it into the flash-open circuitry of a K x which didn't work either.

I came across some NOS blue 15 ohms and green 30 ohms solenoids but it was a waste of money.

Why would you try and install a blue solenoid in the camera. Its has difference specifications from the Green & White solenoids. Its no wonder it didn't work, its the wrong solenoid. I've read the whole post and nowhere has someone suggested installing a blue solenoid.

---------- Post added 02-13-18 at 09:45 AM ----------

I've had a K50 from new since March 2015 and its had no issues whatsoever, until 3 days ago. Was trying out my new DA 55-300 (KAF4 lens, no aperture lever) and it was fine. Swapped back to my 18-135 and I started getting dark frames. Tried again later and all seemed to be ok. It was only about 2 deg C, so it may have been related to the cold.
So I decided to take the casing off and have a look at the solenoid. Took out the horseshoe and put some bevels on the horseshoe tips and carefully sanded the whole thing with some 1200 sandpaper to make the surface smoother. Put it back together and everything still works, so I'll see if the problem re-occurs.
From start to finish the whole job only took me an hour thanks to the guides and comments on here! Fingers crossed!
Thanks to everyone who has contributed to this thread.

[lehoward]

I have twice tried to install a 15 ohms solenoid into the K30. It didn't work.
I also tried to install it into the flash-open circuitry of a K x which didn't work either.

I came across some NOS blue 15 ohms and green 30 ohms solenoids but it was a waste of money.

Thanks for your info. Perhaps the solenoid is driven by a constant current source so a 15 ohms coil could not generate adequate force to release the horseshoe. I will not waste time to trace back the circuit.

[photogem]

Why would you try and install a blue solenoid in the camera. Its has difference specifications from the Green & White solenoids. Its no wonder it didn't work, its the wrong solenoid. I've read the whole post and nowhere has someone suggested installing a blue solenoid

Very simply: Curiosity!

In another thread here in the forum some person tried this solenoid and in one of the Ytube videos this very solenoid from CD Roms is recommended as a cheap replacement.

But one cannot make statements if one hasn't tried something yet!
So first I have to verify it.

The idea was, that a 15 ohms coil which receives the same voltage could work.

But it didn't.

So now I can warn people, not to use those CD-Rom solenoids!

[bigyinn]

Very simply: Curiosity!

In another thread here in the forum some person tried this solenoid and in one of the Ytube videos this very solenoid from CD Roms is recommended as a cheap replacement.

I cannot make statements if I haven't tried it myself.

The idea was, that a 15 ohms coil which receives the same voltage could work.

But it didn't.

So I now I can warn people, not to use those CD-Rom solenoids!

Thats fair enough I guess. Not sure that I'd be brave enough to potentially brick a camera for the sake of curiosity!

[photogem]

Thats fair enough I guess. Not sure that I'd be brave enough to potentially brick a camera for the sake of curiosity!

Well, actually I tried it first on a K100D which was in a pretty rough condition and was a good testunit. It received the filed NOS green solenoid from a K30 after the blue solenoid would not work. It is still running. As it didn't harm the K100D I felt save enough to try it in a K30 with very high shuttercount and in rough condition as well. It didn't work either, but was worth the experiment.

[blindpig]

Hello all,

I've just finished installing a "white" solenoid taken from an MZ-50 in my K30. From the first shot it worked fine! I got the MZ-50 from ebay for £14. The most difficult part of the job was getting the new solenoid in place on the actuator lever and the plastic peg ,but it can be done with some finger gymnastics.
It would have been easier if I'd taken the top off the camera.

Thanks to all who have made videos and thanks to sys3175 who added some information relevant to the K30.

[West Penn]

Regarding the white solenoid in the MZ,-50, does any know when the white solenoid was first used in a film era SLR, or take an educated guess at when that occurred? Seems that knowledge would be helpful for anyone wanting to replace a defective green one.

[lehoward]

Regarding the white solenoid in the MZ,-50, does any know when the white solenoid was first used in a film era SLR, or take an educated guess at when that occurred? Seems that knowledge would be helpful for anyone wanting to replace a defective green one.

Someone in this forum has posted that he used the “white” taken from MZ7. I have disassembled SFX, and Z10 (not MZ10) but the solenoids in both of them are different types.

[bigyinn]

I've just purchased an MZ7 from e-bay for £9.99, so I hope it has the correct white solenoid!
Since performing the sanding on the horseshoe on my K50 it hasn't had any issues, although its had very limited use since. Im hoping to use it this weekend, as I'm dying to try out my new DA 55-300 PLM WR lens.
Assuming the MZ7 works ok, I may well use it for a bit first, as I have some film in my Super A that I'd like to finish off before I carve up the MZ7!