Author Topic: Circuit board catasrophe  (Read 203 times)

anovah

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Circuit board catasrophe
« on: February 09, 2014, 06:24:16 AM »
Unfortunately my TurboDuo was giving me some more audio problems (I had already gone in and replaced the post op-amp caps) and then disaster struck! The entire pad seems to have come up and now I can't attach anything to it.  On top of that, cleaning some of the leakage with isopropyl seems to have exposed some copper.

What have I done?!

I've attached a couple pictures and the first thing that should be clear is that I'm a rank amateur learning on expensive equipment.

Photo #1 has four arrows.  The red one I'm not too worried about except that half the pad did come up and I'm not sure if that's still making a good connection.  The white arrow shows the missing pad and I'm wondering if I can solder the capacitor in at the yellow and black arrows.

Photo #2 is the exposed copper.  There might be a little solder touching it, it's tough to tell.

Basically, I don't know how much damage I've done here or if this thing is even repairable.  I'm hoping I don't have a fancy looking paperweight on my hands.

ANY help is EXTREMELY appreciated.


Keith Courage

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Re: Circuit board catasrophe
« Reply #1 on: February 09, 2014, 06:33:31 AM »
when the pads lift up like that you're left with two options. you can scrape off some of the green trace next to where the pads lifted off of and solder to that instead.


however, what I like to do is just simply run one of the capacitor leeds through one of the via holes next to one of the pads. you can then either solder the lead of the capacitor to the via hole or what I prefer is actually solder the other end of the capacitor underneath the board to wear it actually runs too.
« Last Edit: February 09, 2014, 06:35:11 AM by Keith Courage »

anovah

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Re: Circuit board catasrophe
« Reply #2 on: February 09, 2014, 06:40:19 AM »
Hmmm... that makes sense.  I think I'll run it through the holes like you suggested.  Not sure if it's clear from the picture (I didn't realize how large it was.  Centering it helps) but I think the holes I marked seem like the best candidates.  (I really know very little about electronics)

Also, does the exposed copper in the second picture seem like it will be an issue?  It frightens me  :shock:

BlueBMW

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Re: Circuit board catasrophe
« Reply #3 on: February 09, 2014, 09:17:26 AM »
Anytime I get exposed copper like that I just coat it with a thin layer of solder to keep it sealed up from corrosion.  It actually happens quite a bit when the electrolytic fluid gets in there and starts eating the copper.  It tends to make the solder mask (green stuff) come loose.
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anovah

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Re: Circuit board catasrophe
« Reply #4 on: February 09, 2014, 10:57:55 AM »
Whew, that's reassuring.  This project might be salvageable yet.

I want to try running the caps through the holes but am still a touch sketchy on which ones to use.

Keith Courage

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Re: Circuit board catasrophe
« Reply #5 on: February 10, 2014, 11:50:58 AM »
Just follow the green traces that run to the pads that fell apart.
« Last Edit: February 10, 2014, 04:55:49 PM by Keith Courage »

deubeul

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Re: Circuit board catasrophe
« Reply #6 on: February 11, 2014, 09:05:15 PM »
Multimeter is your friend  :wink: