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geekhack Community => Keyboards => Topic started by: phinix on Sun, 10 March 2019, 09:02:02

Title: Soldering problem - SOLVED
Post by: phinix on Sun, 10 March 2019, 09:02:02
Hi guys.
I need help. I was working on my first ever re-soldering project - I desoldered Varmilo VA69M and soldered Tealios on it.

However, as I don't have an soldering experience, I messed up few places and now 3 switches don't work.

I'm wondering if this can be fixed or did I killed £170 worth of board... :(

Please see those images, first one is up arrow - I think, I THINK... when I was taking off old switch I also took out that small ring that was on the pcb. Then I noticed that this thin long thingy - don't know how you call it - is coming off. It looks like a thin copper "route"?
I soldered it to that spot, but switch still not registering.

Second photo is "\" and "Z" - both not registering. One has lost this small ring on pcb, but other one was fine.
Please ignore those burnt holes over the switches - those were leds - I was not able to get rid of them easily:(
I know...baaaad soldering...

Is ther a way to fix those? Can I somehow "re-wire" them?

[attachimg=2]

[attachimg=1]

Title: Re: Soldering problem - need help !
Post by: suicidal_orange on Sun, 10 March 2019, 09:17:23
The thin strips of copper on PCBs are called traces :)

All you need to do to fix this is run a wire where the trace should go - in the top pic that's clearly from the bottom switch pin to the bottom of D108.

\| and Z are connected on their top pins so chances are this should continue.  If you touch the bottom pin (right of the Z label) to the top pin of X does it output a Z?  If it does solder a wire between the top pins of those switches.  Repeat for \| which may or may not work after fixing Z.
Title: Re: Soldering problem - need help !
Post by: fohat.digs on Sun, 10 March 2019, 09:17:46
Repairing broken traces can be done but it is not easy. You will have to expose something that you can make an electrical connection to, probably by scraping off a portion of the green mask, and then making a tiny connection to it.

That is just the principle of it, I have never had much luck actually doing it since I am not much more than semi-competent in the soldering department. If you know anybody with small hands, sharp eyes, and top-shelf equipment you should seek their help.
Title: Re: Soldering problem - need help !
Post by: tp4tissue on Sun, 10 March 2019, 09:43:15
In the first picture, take a copper wire,  cut an old cable and pull out the copper,   And bridge the 2 points.


The SECOND picture, it looks like maybe cold joint..


Next time don't use lead free solder.
Title: Re: Soldering problem - need help !
Post by: phinix on Sun, 10 March 2019, 09:59:49
Thanks guys - arrow is now fixed!! :)

I wired that D108 with it and arrow now works:)

Now those Z and |\ - they in deed are connected with top pins. I have connected them with wire but still not working.
Maybe the problem is with Z bottom pin - I lost that small ring when desoldering - I just don't know what should I re-wire it with...

I hope that makes sense. WHat do you guys think?
Title: Re: Soldering problem - need help !
Post by: suicidal_orange on Sun, 10 March 2019, 10:04:09
Now those Z and |\ - they in deed are connected with top pins. I have connected them with wire but still not working.
Maybe the problem is with Z bottom pin - I lost that small ring when desoldering - I just don't know what should I re-wire it with...

If it was the bottom ring of Z that got damaged that should be joined to the bottom of D11, then try the test above again (touch bottom pin to top pin of X) - it wouldn't work if both were broken :))
Title: Re: Soldering problem - need help !
Post by: phinix on Sun, 10 March 2019, 10:12:46
Now those Z and |\ - they in deed are connected with top pins. I have connected them with wire but still not working.
Maybe the problem is with Z bottom pin - I lost that small ring when desoldering - I just don't know what should I re-wire it with...

If it was the bottom ring of Z that got damaged that should be joined to the bottom of D11, then try the test above again (touch bottom pin to top pin of X) - it wouldn't work if both were broken :))

Cool.

So, when touching bottom Z with top X, it registers X. What does it mean?
Title: Re: Soldering problem - need help !
Post by: suicidal_orange on Sun, 10 March 2019, 10:15:12
It means soldering the top pin of Z to the top pin of X will make Z work.  And probably |\ too :)
Title: Re: Soldering problem - need help !
Post by: phinix on Sun, 10 March 2019, 10:30:09
It means soldering the top pin of Z to the top pin of X will make Z work.  And probably |\ too :)

Cool. I did that - now Z registers X and |\ registers "F1":(

What the hell is wrong with those two?
Title: Re: Soldering problem - need help !
Post by: suicidal_orange on Sun, 10 March 2019, 11:02:58
Oops - misread this X as a Z :-[
So, when touching bottom Z with top X, it registers X. What does it mean?

Needless to say you need to unsolder X-Z.  Try touching the top of A or S to the bottom of Z - you're looking to register a Z press...
Title: Re: Soldering problem - need help !
Post by: phinix on Sun, 10 March 2019, 12:01:47
Oops - misread this X as a Z :-[
So, when touching bottom Z with top X, it registers X. What does it mean?

Needless to say you need to unsolder X-Z.  Try touching the top of A or S to the bottom of Z - you're looking to register a Z press...

Cool, I'll try that now - thanks for helping me with this - it is totally weird for me:)
Title: Re: Soldering problem - need help !
Post by: phinix on Sun, 10 March 2019, 12:16:30
Oops - misread this X as a Z :-[
So, when touching bottom Z with top X, it registers X. What does it mean?

Needless to say you need to unsolder X-Z.  Try touching the top of A or S to the bottom of Z - you're looking to register a Z press...

Cool, I think I found it :
- top A + bottom Z = Z
- top A + bottom |\ = \

What should I do now?
Title: Re: Soldering problem - need help !
Post by: suicidal_orange on Sun, 10 March 2019, 12:26:39
Solder from the top of A to the top of |\ or Z (whichever has the least components to go round) and put it back in the case as it will be working properly.

Then go get some dinner :thumb:
Title: Re: Soldering problem - need help !
Post by: phinix on Sun, 10 March 2019, 14:03:39
Solder from the top of A to the top of |\ or Z (whichever has the least components to go round) and put it back in the case as it will be working properly.

Then go get some dinner :thumb:

Awesome! Thank you very much for help - it works fine now:)
My first resoldered keyboard is now completed - without your help it would be a disaster:)

Now I can have a dinner:)