geekhack
geekhack Projects => Making Stuff Together! => Topic started by: Photoelectric on Mon, 09 June 2014, 11:21:53
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I have a keyboard with a broken mini USB socket area. Basically looks like it got ripped out at least partially and then resoldered? Not entirely sure how it went down, but that's my best guess, looking at the current condition. I took some high magnification photographs to try and see what's going on. Plugging in a USB cable, the board does not get recognized at all. My best guess is that the 5 wires from the mini USB sockets all have their signals mixed due to the area where they attach being all roughened up and exposed and inter-conducting. I'm not sure how to isolate individual traces. Does anyone experience with fixing this sort of damage?
(http://i.imgur.com/n8zgkeB.jpg)
Photo album here: http://imgur.com/a/sFBxA#0
I have brand new replacement mini USB sockets, but the issue is with isolating those traces, I think...
Taking off the socket, here's what's underneath. The closest left pad has been lifted. There are 3 traces sticking out for the 5 USB wires, if I'm identifying them correctly--not sure where the 2 remaining traces are :(
(http://i.imgur.com/wVTHXqe.jpg)
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ouch! that hurts just looking at.
There should be 5 connections, of which 4 are strictly necessary. The lifted pad isn't too big a deal as it's just for stabilization (still I would be extremely careful with the USB port after this)
Sadly, there's still a lot of "crud" (looks like what comes out of my soldapullt when I clean it) around the area. I can't begin to estimate further damage (if any) until it's gone.
I do see a few lifted traces, but I also notice that a few of them go to those nearby pads, so it's repairable with care.
The easiest will be to replace the PCB, but It is still probably salvageable at this point. You also might want to reflow the switch on the left, looks like there's too much solder on one of the pins (not that it'll hurt, but wight as well do it while the iron's warm anyway)
So I recommend cleaning the PCB, which may require heat to clean up that gunk if it is indeed solder residue as I suspect.
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Yeah, there's some gray-colored gum-like gunk around where the traces are exposed. I'm afraid to subject it to any additional heating until rewiring. What's the best way to clean that up? I can scrape it off with tweezers, but not cleanly.
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Yeah, there's some gray-colored gum-like gunk around where the traces are exposed. I'm afraid to subject it to any additional heating until rewiring. What's the best way to clean that up? I can scrape it off with tweezers, but not cleanly.
Hmm, I'm not sure. Have you tried lots of flux and then alcohol?
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Yup :( I need stronger alcohol--my bottle's almost out and probably partially evaporated/diluted now.
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Looks like the previous owner tried to use some conductive glue to fix the contacts... yuck. Not an easy fix I'm afraid.
I'd say scrape what you can, try to get the rest off with flux and solvent. If there are enough traces intact, solder a new socket on and use small wires to bridge from the socket pin to a contact on the board for the ones that have lifted.