[photogem]

Solenoids tend to be very simple electromechanical devices and their mode of failure is consistent: the insulation between the coils, some number of micrometers in thickness, simply shorts out and renders the device "no worky".

Better to study the history-thread first:
A LITTLE BIT OF HISTORY: Development of the solenoid in Pentax cameras - PentaxForums.com

There never was any problem with the coils.

In the 1950s and 60's my grandfather had a repair shop that rewired armatures of various kinds, usually for generators and alternators of automobiles, but sometimes also the odd appliance. The tooling nor the process is not complicated, and these days you can order fresh wire that's already been uniformly insulated to tight tolerances, unlike the dangerously hot shellacking my forebearers, including my child father, gleefully performed by hand without respirators.

Perhaps there are a couple mechanical engineers on this site that would be interested in designing simple tooling for a rewinding apparatus that could be 3D printed.

In the past I had a person who wound coils, transformers etc. for me. He used a winding-machine without a motor, modern (and super expensive)
machines of course do it automatic and do count the windings etc.


So even if it would be a coil problem, for those tiny coils you need a special winding-machine.
Same for winding coils for moving-coil- or moving-magnet-cartridges (that is for audio though, not for guns)

[ismaelg]

STOP the killings and the madness!

Member of the 6MP lovers club...

[Ronald Oakes]

STOP the killings and the madness!

Member of the 6MP lovers club...

The Who ... the what Club?

[Ronald Oakes]

Just was thinking.....
Maybe I could harvest the white solenoid from the flash of the *ist DL rather than the inner one and then replace it with the green one from the KS2 ?
That way the KS2 lives ! ...... And the *ist DL is minorly handicapped rather than murdered outright ? Worse case scenario is the flash won't pop up ! Best case scenario is it might even work properly.......
Much like sharing an extra kidney where both Live !

---

Last edited by Ronald Oakes; 04-23-2022 at 06:02 PM.

[photogem]

Just was thinking.....
Maybe I could harvest the white solenoid from the flash of the *ist DL rather than the inner one and then replace it with the green one from the KS2 ?
That way the KS2 lives ! ...... And the *ist DL is minorly handicapped rather than murdered outright ? Worse case scenario is the flash won't pop up ! Best case scenario is it might even work properly.......
Much like sharing an extra kidney where both Live !

1. The *ist DL would only be minorly handicapped if you'd sell it without letting the buyer know it got a green solenoid in the flash-circuit.
2. The pop-up-flash of your *ist DL won't pop up only if you make a mistake there. The green China solenoid had been tested there over many years and never failed there.


So not so much a kidney transplant but more like a skin transplant

[Ronald Oakes]

My soldering iron was too big and unwieldy. Although it worked for the last 3 surgeries , it was just waaaay to hot also. I don't want to fry anything.

Decided to get this off Amazon for less than $10. It looks much more appropriate for delicate operations , and will be much easier to manipulate .
https://www.amazon.com/Soldering-Iron-Kit-Temperature-Rarlight/dp/B07PDK3MX1...%2C213&sr=8-20

[photogem]

My soldering iron was too big and unwieldy. Although it worked for the last 3 surgeries , it was just waaaay to hot also. I don't want to fry anything.

Decided to get this off Amazon for less than $10. It looks much more appropriate for delicate operations , and will be much easier to manipulate .
Soldering Iron Kit, [Upgraded] 60W Adjustable Temperature Welding Tool with ON-Off Switch, 9-in-1 Soldering Kits, 5pcs Soldering Iron Tips, Solder Wire, Y Type Soldering Iron Stand (Light Blue) - - amazon.com?tag=pentaxforums-20&

Looks like a very nice option.
The tips look similar to the more simple Weller ST tips for the soldering iron in red color.
All Weller soldering irons are now made in China anyway, the transformers for the stations in Mexico.
So they developed similar soldering irons based on what they learned doing the Wellers.
Well spent money I think

[Ronald Oakes]

Well.... my donor body arrived today and I promptly got right to the surgery.
All went very well as this was my fourth green solenoid swap. Right at the end I was pulling my hair out for about a half an hour trying to figure out why all of my exposures were coming out severely Overexposed Almost White. Just when I was about ready to give up I discovered that my exposure compensation somehow got locked in the process.
The *ist DL however didn't fare so well. I couldn't for the life of me find a diagram online on how to remove the solenoid from the flash properly without destroying everything. Unfortunately in the process I broke the damn thing and then got frustrated and just got right down to business and pulled both solenoids out. She did get even with me though and I got one nasty shock that I don't ever want to experience again !!!
On a side note I did find a small metal shaving stuck on the magnet of the solenoid. I have no idea what it came from but I don't think that it affected the performance but I'm not sure.
I also had a question about the magnet in the solenoid and whether or not it was position sensitive in other words does it have a positive and negative end?
Overall my agenda was nicely completed without any real issues. I do kind of feel bad though about the *ist DL but that's just the way things go and I really didn't need to be playing with yet another camera.
I need to take some pics of this solenoid for Photogem to take a look at , and I also have a spare white one out of all of this.

On an interesting note....I swear my screw holding the solenoid was on the left ???
Too late to go back and double check now. I hope I got it in the right place.

[photogem]

The *ist DL however didn't fare so well. I couldn't for the life of me find a diagram online on how to remove the solenoid from the flash properly without destroying everything.

The threadlocking laquer can be quite strong. Then one needs good patience to losen the solenoid on the metal base it is sitting on.
First one unsolderes the 2 wires. Then one losens 2 screws, one which holds the metal base, the other the solenoid itself. Now this metal base can come off easely. If one wants to swap solenoids because the *ist ist still alright, one has to make sure that the tiny black plastic rod is not going to be lost.

It is the same as HERE with the K-x!
The laquer can really be quite strong, I then lever the solenoid gently up and down at the plunger and carefully bring a razorblade or scalpell between the solenoids metal body and the metal base until it all the sudden lifts.

She did get even with me though and I got one nasty shock that I don't ever want to experience again

If one forgets to discharge the flash condensor she turns into an electrophorus electricus

On a side note I did find a small metal shaving stuck on the magnet of the solenoid. I have no idea what it came from but I don't think that it affected the performance but I'm not sure.

I daubt it as well

I also had a question about the magnet in the solenoid and whether or not it was position sensitive in other words does it have a positive and negative end?

I think so

I need to take some pics of this solenoid for Photogem to take a look at , and I also have a spare white one out of all of this.

Will be interesting

On an interesting note....I swear my screw holding the solenoid was on the left ???
Too late to go back and double check now. I hope I got it in the right place.

Late K-S2's already had the late diaphragm control block similar to the K-70, the only difference being the screw on the left side and usually the 2-nd generation of the China solenoid.

[tonyzoc]

I wouldn't say I'm laughing quite yet. I envy people that have never had ABF on the usual suspect bodies. I'm now 3 for 3.

I'm not short on camera bodies by any means , but I use my K-S2's daily and dearly love them.

My beater K-S2 has already been given the appropriate transplant about a year ago and never missed a beat since. 50K clicks now.

This K-S2 was one of the very last ones made. Supposedly largely immune from ABF....Yet here it is again at 3K clicks.

I'm very stressed and aggravated , but what else can I do ? May as well have some fun with the situation...

---------- Post added 04-20-22 at 15:45 ----------



I assumed by my cameras manufacture date and later serial number that it has the second modification ?

But since it is failing something is still wrong.

I have done a few solenoid repairs and wouldn't think of putting anything in except for the white original.

Will keep you posted on the transplant , and identifying which version it currently has.

Well you've topped me...I had it twice with the K-S2 and one on the K70. 3 times on 2 bodies

[photogem]

Well you've topped me...I had it twice with the K-S2 and one on the K70. 3 times on 2 bodies

From personal cameras I used:
K30
K50
K-S1
K-70
but no competition.
I am quite positive that with the latest solenoid modifications the late K70 is no longer in any danger of developing ABF.

[Ronald Oakes]

From personal cameras I used:
K30
K50
K-S1
K-70
but no competition.
I am quite positive that with the latest solenoid modifications the late K70 is no longer in any danger of developing ABF.

But isn't that the same solenoid that was in my K-S2 ?

[photogem]

But isn't that the same solenoid that was in my K-S2 ?

You mean somehow this solenoid from your K-S2 made its way into first my K30, then K50, then K-S1 and then my K-70
That would be a real satire

[Ronald Oakes]

You mean somehow this solenoid from your K-S2 made its way into first my K30, then K50, then K-S1 and then my K-70
That would be a real satire

You said the latest solenoid modification made the k-70 largely immune from ABF ? Im assuming you were referring the the second modification on the solenoid from Pentax ? What do you call it gen 2 ? Or did you replace it with a white one to avoid ABF ?
But that is the same solenoid that was present in the last batch of K-S2's such as I have ?
Or am I missing something here and the late model K-S2's have a different solenoid than the latest K-70 models that are made ?
Quite lost....

[photogem]

You said the latest solenoid modification made the k-70 largely immune from ABF ? Im assuming you were referring the the second modification on the solenoid from Pentax ? What do you call it gen 2 ? Or did you replace it with a white one to avoid ABF ?
But that is the same solenoid that was present in the last batch of K-S2's such as I have ?
Or am I missing something here and the late model K-S2's have a different solenoid than the latest K-70 models that are made ?
Quite lost....

I think that the last modification of the solenoid was done quite recently (to name it "Generation 3" would be correct) But I have no idea when they did it and no idea about serial numbers (K-70 only!)


Your K-S2 had the first modification, i.e. "Generation-2"
This was already better (introduced Dec. 2015) but hit a few with ABF.
It was better but not perfect yet

See: