Best way to repair broken PCB tracks?

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EdGs
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Re: Best way to repair broken PCB tracks?

Post by EdGs » Thu Aug 25, 2016 12:56 am

I have used low temp magnet wire to repair damaged traces. IMO it is relatively easy because you can tin a small bit on the end of the wire and attach it to a solder pad on one side of the break, trim to length, then repeat on the other side of the break. It takes a couple seconds to burn through the insulation on the wire, so it is durable.

It would be a bit harder on the component side, but doable. I like 28 to 30 awg for the small traces. The component side would potentially be a bit harder, but I would take a shot if it were mine.

Mooger5
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Re: Best way to repair broken PCB tracks?

Post by Mooger5 » Fri Aug 26, 2016 12:11 am

Thanks for the reply. I´ve used a Roadrunner wire pen and wirewrap wire in the past to repair a few isolated traces.

What troubles now is a good number of components have to be desodered, including the secondary CPU.

Have nothing to lose, besides time. As soon as the fiberglass pen arrives I´ll try to fix the board.

Edit- if only wire jumpers and no conductive ink, solder paste or wire bridges are to be used, then there´s no need to desolder anything. Components will be perfectly accessible from the opposite side. My moment of genius heh. Then I´d be able to glue the PCB to prevent it from further damage.
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Re: Best way to repair broken PCB tracks?

Post by Mooger5 » Wed Sep 28, 2016 10:09 pm

The replacement motherboard cost about 140 euros after duties. It was just plug and play. Not the solution I originally had in mind, but hey it´s fixed.

Now for the keybed. The synth had been in storage for a decade, completely dismantled. The contacts got dirty or oxidized and I fixed most of them by pressing one against the other while activating the respective key. I guess contact cleaner will be a more durable solution. One full octave though remains silent as the contacts got bent. Thinking of desoldering and straighten them out. Or to get a replacement part (which will add to the cost). What would you pros do?
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Re: Best way to repair broken PCB tracks?

Post by Mooger5 » Thu Sep 29, 2016 11:35 pm

So it´s not necessary to desolder the contacts. I fixed most of them now. Two remain silent and I´ll fix them tomorrow. B4 and C4 though working, sound too quiet no matter how hard I hit them. Does anyone know what´s causing it? There are three metal plates underneath each key. The faster the middle plate goes from the top plate to the bottom plate the "louder the sound" so to speak. The middle one is making contact to bottom plate for sure. Is it not making contact with the top one? The CPU lacking data would then play the sound at minimum possible velocity. Is this right?
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Re: Best way to repair broken PCB tracks?

Post by Mooger5 » Sat Oct 01, 2016 2:52 pm

OK I got it: when in rest, the moving stripe is always in touch with the top stripe. When a key is depressed its central stripe moves away from the top one opening the circuit, in fact "unmuting". This will sound at the lowest velocity value until the moving stripe meets the lower stripe. How fast it makes contact determines the value. B4 and C4 had their lower stripes too far away from the moving stripes. C4 was an easy fix but B4 was a lost case. After so much bending and unbending the poor metal stripe gave its final fart and snapped off. The other silent keys were just broken. Replacements ordered and this board will be fully functional by the end of the week. What to do with it, since I bought a mint mkI and I´m in love with that thing. Such an expressive piece of "antediluvian technology" as someone said (tried MIDI Local ON, Brian? :) ).
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Re: Best way to repair broken PCB tracks?

Post by Soldertraining » Fri May 19, 2017 3:13 pm

If this is the first time you solder or repair some PCB tracks then I would suggest, rework on an old PCB board.

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Re: Best way to repair broken PCB tracks?

Post by Mooger5 » Fri May 19, 2017 10:50 pm

LOL no s**t?
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