[ChristianRock]

It isn't worth fixing! Too much got damaged by heat and wrong soldering with the flame of the butan-gas soldering-iron!


Not really. I have answered that one in detail HERE but I cannot agree with:

Having repaired quite a few of both of them, I would say, that without instructions finding out about the hidden screws of the K-S1 is pretty difficult.
But we have those instructions and in my experience the difficulty-level is almost on the same level.

I did follow your instructions and found them extremely helpful. I see no issues with them at all. But I do think the chassis of the K-S1 is a lot thinner, easier to break the little plastic joints, and so it must be handled quite a bit more carefully than the K-S2, which you basically unscrew and take apart. That is all.

[pishta]

I'm doing the repair today. Disassembly was easy. Getting the green solenoid out was easy too. But...I thought the bottom part of the solenoid fell inside the camera and I couldn't find it...turns out it just flipped behind the top of the solenoid. I've attached a couple of pics of the base piece.

Had a hard time soldering the wires back on. Finally got it though.

One last problem before reassembly. This part fell out and I don't know where it came from...last photo.

This is a "california" filed plunger, I found the exact one in my used K50. When they file the ends, it makes the breakaway force very light and I believe it slows the duty cycle of the stop down to the point that the shutter may overrun the stop down event if that is even mechanically possible? The White one I replaced it with has a nice crisp breakaway and the action is very tight sounding now. The filed (weakened) plunger shutter trip sounded like my old AE-1 when the shutter was in need of lubrication, very drawn out. After I lubed it, it was crisp like the white solenoid action.

[photogem]

This is a "california" filed plunger, I found the exact one in my used K50. When they file the ends, it makes the breakaway force very light and I believe it slows the duty cycle of the stop down to the point that the shutter may overrun the stop down event if that is even mechanically possible? The White one I replaced it with has a nice crisp breakaway and the action is very tight sounding now. The filed (weakened) plunger shutter trip sounded like my old AE-1 when the shutter was in need of lubrication, very drawn out. After I lubed it, it was crisp like the white solenoid action.

We already verified this long time ago.

Simplicity can be helpful, if combined with experience, knowledge and logic:
1. Your K-S2 had been repaired previously in what others see as a nice neat job but actually is the very opposite, i.e. prepared for further problems up to disaster
2. You took on the task to repair it but things went wrong, partly due to to the disasterous work done by the California workshop:
Due to not only applying a wrong repair method i.e. sanding and filing the plunger but doing this work in the utmost wrong way the plunger did not hold proberly anymore but fell into your camera: This could have led to further damage
3. As I have explained many many times: When one applies the rotten filing sanding method the complex mechanism can come into disorder, out of alignement up to
further damage.

The sound you presented which is not he SR came after the rotten sanded solenoid turned went faulty again!
I.e. the sound could possibly be linked to the complex mechanism having gone out of alignement!.....

But the problem here was that more was damaged due to the use of a butan-gas soldering iron.
Too much heat which damaged other parts.

[tonyzoc]

We already verified this long time ago.

But the problem here was that more was damaged due to the use of a butan-gas soldering iron.
Too much heat which damaged other parts.

Correct... I used an electric adjustable soldering iron for my K70 and the (white solenoid) repair went fine and the camera has been working perfectly for 2-3 years now.

[Itbejames]

We already verified this long time ago.

But the problem here was that more was damaged due to the use of a butan-gas soldering iron.
Too much heat which damaged other parts.

I’m thinking about acquiring a used ks-2 that has the aperture block syndrome as a backup to my k-70. I already have a white solenoid from potsamo out in California. I have experience in soldering and use a Weller temperature adjusting soldering station. What temperature and solder do you recommend?

[photogem]

I’m thinking about acquiring a used ks-2 that has the aperture block syndrome as a backup to my k-70. I already have a white solenoid from potsamo out in California. I have experience in soldering and use a Weller temperature adjusting soldering station. What temperature and solder do you recommend?

This depends on the solder you use. I use "vintage" leaded solder without resin-flux which isn't so easy to find.

A tiny amount of fluxpaste (copntains rosin = colophony*) goes onto the pins of the solenoid and if one wants a tiny amount onto the bare ends of the two wires.
Then a tiny amount of solder onto the hot tip (I use 350 Celsius). It doesn't smoke because it is fluxless.
Then with some tweezers or small precision pliers I hold the wire onto the pin, add the liquid solder with the tip of the soldering iron, it flows and smokes (the colophony)
short wait until hard, easy and straight forward.
This is the old fashioned way of soldering and here I like it the best.
I wouldn't recommend silver-solder but leaded solder if you can buy it.
A good unleades solder is "wonder-solder", it melts at lower temperatures.

But more important is the size of the tip. My Weller soldering-station holds the temperature right into the tip very stable.

[pishta]

I used 370C and a pretty small tip (smaller tip can take higher heat) and I just touched the 2 wires together with the iron and i got an almost instant melt and bond. There was enough solder on the unsoldered wire I removed to tack it back on like a pro. Its not a strength weld its only a contact weld so as soon as it flows your done! give it 5 seconds to cool and gently pull on the wire, If it sticks, its good as there is no movement on this joint.

[photogem]

I used 370C and a pretty small tip (smaller tip can take higher heat)...

You probable mean something different here because a larger tip can take higher heat as well.

A smaller tip will have the same temperature as does a larger if the soldering iron is temperature controlled (as in your case)

I use the Weller WS81 pro station
I have two different "pencil tips", quite similar in shape but one is longer: The =LT+Soldering+Tips]LT1 and LT1L

The temperature-control is right beneath the tips, so one of the better ways to achieve precise and stable temperature.
The longer LT1L tip always needs some extra degrees to melt the same solder than shorter LT1 pencil tip!
Same for larger or very large tips.

....and I just touched the 2 wires together with the iron and i got an almost instant melt and bond.

You probably mean you touched the wire onto the pin of the solenoid with your iron-tip?!

There are no two wires which need to be soldered together.

Anyway, this method is not a good one, it is what we call "glueing instead of soldering".

For correct soldering the two parts being soldered together they most not move but remain still!
With your method as soon as you remove the soldering tip there will be movement.
But for the solder to cool down and hold perfectly this movement will cause the wire to move in the "cooling" solder and this is a bad soldering connection,
we also call it a "cold solder point".

One of the typical mistakes to be avoided!

Also holding the wire to the pin with the tip could do damage to the pin!

There was enough solder on the unsoldered wire I removed to tack it back on like a pro. Its not a strength weld its only a contact weld so as soon as it flows your done! give it 5 seconds to cool and gently pull on the wire, If it sticks, its good as there is no movement on this joint.

There might be no movement but it still most likely is a cold solder point.

The correct way is to add solder to the pin and solder to the bare end of the wire.

Then you hold the bare end of the wire with some tweezers or similar to the pin and touch both with the soldering iron tip.
This will bring the solder on both to melt, you retreat the tip, keep holding the wire very still until the solder is cold.
You don't even blow onto the solder to cool it down quicker a common mistake for a bad contact!

Because for such work one would be best off with 3 hands, I instead use solder without resin and apply the resin to the pin and bare end of the wire.
Then I apply the solder onto the tip (it won't smoke because there is no resin) and then continue the way described.

Of one cannot find resin-free solder, one uses normal (best leaded) solder and one can even make resin oneself:
A Recipe to Make Your Own Natural Rosin Soldering Flux - Hackster.io