# Solenoid Soldering help



## suraswami (Sep 18, 2017)

Hi,

One of my Beloved cameras developed Aperture block failure and to fix I need to replace a solenoid.

Read-up Pentax K50 aperture block failure and there are several youtube videos too (for people interested).














 

I removed the horse shoe magnet to check it out.

The picture shows the donor solenoid from a dead camera.

I haven't done soldering on such tiny part, so question:

Many want to remove the solder on the solenoid from the wires and solder to the wires on the camera that needs a fix.  But I am worried that the plastic above the coil might get damaged if I touch it more.

So can I cut the wires and join the wires on the camera that I want to fix?

One person suggested to use shrink tube, again I don't have enough space inside the camera to shrink the tube with a heat gun.

Can I just use good old electrical tape?

Any other alternative?


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## erocker (Sep 18, 2017)

Removing the solder isn't too difficult. Just place your iron on the solder, the second it liquefies, suck it off. It isn't necessary though and if the solder on there looks decent (not burnt or corroded) you connection should be good.

You can clip the wires off and leave a bit of wire to solder the new wires to. Easiest way to connect the new wires is to add solder to the wires (then let harden) before connecting. Then just place the wire on the connection point and iron.

A little vice will help a lot. Something like this:
https://www.amazon.com/dp/B000B61D22/?tag=tec06d-20


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## suraswami (Sep 18, 2017)

These are the things I put on hold at MC

http://www.microcenter.com/product/461181/Soldering_Tool_Kit_-_ETL_Approved

http://www.microcenter.com/product/434131/Helping_Hands

Hopefully I don't mess it up.

With my tired old eyes and broken hand is it better to solder wires rather than soldering on the solenoid metal part?


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## suraswami (Sep 19, 2017)

YAY!! fixed it. I learned how to Solder too.

I got help from my son to hold flash light and hold the tiny wires while I 'desolder' and solder it back. He enjoyed working with me and fixing the camera.

Soldering I wouldn't say it's best but for now it's holding up.

I have to open and close the camera at least 3 times.

First time I opened, Desoldered, soldered, then put the body together without much screws to just test the camera.
Next with all the excitement I put in all the screws that I put on my camera drawing paper to find out I have one screw left that said inside camera.
So opened the camera again, but brilliant me, didn't map where that one screw would go, so wasted time in figuring out and watching Youtube videos. Finally found the spot and assembled everything together.
Testing all the camera buttons to see if everything works as it should, nope the left side focus lever while turning from AF-A to C got stuck at MF. Crap, I have to open the camera all over again.
While opening I got a whirrr shock from the camera, not pleasant lol. Fixed the lever and put everything together, working good so far.

For an experienced person it would have took max 30 min to open and fix it. I started at around 9 PM (after practicing soldering on an old computer exhaust fan wire) and finished by 3 AM (with that many times opening and closing the camera).

This morning it seems to work fine with the Fully charged OEM battery. First short exposure turned out spot on.

Going to further test this evening.

Was going to take a time lapse video but it was too late and I wasn't sure how well the operation will turn out.

Will post pics when I get a chance.


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## suraswami (Sep 20, 2017)

Here are some pics
Donor Solenoid ripped from a dead camera


 



 

 

 
After Soldering the Solenoid


 



 

The dying one


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## AsRock (Sep 20, 2017)

Glad ya got it fixed.

If you cut the wires you might be adding length which MAY be a problem. But should be able to pick up some shrink wrap 2mm for about  $1.50 for 5 meters  on ebay. Could pay a little more for it some that shrinks more than 1/2 the original Diameter.
Take the one of the broken camera and you will see how hard or easy it will be.

Can you not do it from the circuit board ?.

Shame i  have a K1000 as spares that might have the same one in it.


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## suraswami (Sep 20, 2017)

AsRock said:


> Glad ya got it fixed.
> 
> If you cut the wires you might be adding length which MAY be a problem. But should be able to pick up some shrink wrap 2mm for about  $1.50 for 5 meters  on ebay. Could pay a little more for it some that shrinks more than 1/2 the original Diameter.
> Take the one of the broken camera and you will see how hard or easy it will be.
> ...



I soldered the solenoid directly, works fine, Solder not the best but if it breaks off I will cut the wires from donor camera and join to this.

Yes the wires can be desoldered from the board, pretty easy, some do that too.

I tried the shrink wrap on a case fan wire.  problem here is limited space, don't want to damage neighboring components.


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## AsRock (Sep 20, 2017)

Yeah camera's are tricky, be really careful messing with the flash part as the clip can mess up which holds the flash down.


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## leonidas09 (Mar 11, 2019)

erocker said:


> You can clip the wires off and leave a bit of wire to solder the new wires to. Easiest way to connect the new wires is to add solder to the wires (then let harden) before connecting. Then just place the wire on the connection point and iron.



Oh man thank you!
And thanks to all about this info! You saved me my sanity!


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## eidairaman1 (Mar 11, 2019)

suraswami said:


> Hi,
> 
> One of my Beloved cameras developed Aperture block failure and to fix I need to replace a solenoid.
> 
> ...



Here's the thing as long as you have additional wire that is the same gauge as the wire inside the camera, you can solder on to Pieces onto the new solenoid and then cut the old one out of the camera and then solder the wires


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## suraswami (Mar 12, 2019)

1.5 yrs after surgery, the camera still kicks a**!!


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## leonidas09 (Mar 12, 2019)

eidairaman1 said:


> Here's the thing as long as you have additional wire that is the same gauge as the wire inside the camera, you can solder on to Pieces onto the new solenoid and then cut the old one out of the camera and then solder the wires



Is there any chance we know the gauge of this cable? Just in case..


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## eidairaman1 (Mar 12, 2019)

Wire in us is measured by AWG there is no clue with some cameras etc


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## leonidas09 (Mar 12, 2019)

eidairaman1 said:


> Wire in us is measured by AWG there is no clue with some cameras etc


I was searching in eBay for such wires and found that there are varying from 12 to 30 AWG, so I thought that maybe someone might know it, or be a technician of some kind and could find it using some kind of equipment.


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## eidairaman1 (Mar 12, 2019)

Ok 12 AWG is bigger/thicker than 30


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## AsRock (Mar 13, 2019)

Could try getting your hands on some broken gear, mainly from those with SMPS, some have real small ones in them.


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## leonidas09 (Mar 13, 2019)

AsRock said:


> Could try getting your hands on some broken gear, mainly from those with SMPS, some have real small ones in them.


Ok thank you!
I'll keep that in mind if something goes wrong again!
Right now it seems it works well.
Thank you all guys!


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