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Recapping gone wrong

nyef

Active member
Looking at the picture you provided, they both have surface-level traces (easy to expose with a fibreglass pen or craft knife and solder a patch wire to), and both lead to VIAs (typically already exposed, and easy to solder a patch wire to).  Or if you're careful, you could even just leave one of the component legs for those radials you're using a bit long and use that instead of a patch wire.

Overall, this very much looks rescueable without reference to a circuit diagram or trying to do a pad repair.

 

Macdrone

Well-known member
looks like you need to clean more from the start and use more flux.  Just a suggestion.  When I am just trying to get boards to work I take shortcuts, but as you can see it never turns out very well.

 

IIfx

Well-known member
I would restart with proper SMD caps. Japanese aluminum polymer would be a way better choice instead of cheap generic electrolytic caps.

Solder paste makes these jobs much easier.

 

nyef

Active member
The first couple of times I recapped something, I used radial caps to replace SMD. It works, more or less, but tends to be ugly. In one case, I simply couldn't find compatible SMD caps, so had to use radials, and then had trouble getting the case closed. I very quickly got tired of buying "capacitor kits" for specific hardware, especially since sometimes they aren't quite right, and moved up to simply stocking a goodly range of capacitor values in common packages. With a little bit of practice, SMD, at least of this vintage, tends to be fairly easy to work with, as long as I can get my iron to the terminals (not always guaranteed with the way some boards are laid out).
 

Solder paste makes these jobs much easier.
I've never actually tried solder paste. I know that it supposedly works well with hot air, but does it also work well with an iron?  If so, I can absolutely see that simplifying things, simply because you have fewer things to either keep steady or move carefully at the same time.

 

IIfx

Well-known member
Solder paste when used with a good iron will just magically melt and adhere to only the pad and the SMD contact leg. All you have to do is carefuly apply just enough paste, hold down the part with tweezers, apply heat with the iron to the pad and leg, and then clean the board to remove any remaining paste. Contact cleaner does the job cleaning.

99% of the solder paste will naturally gravitate to the pad and lead. It's amazing stuff.

 

Floofies

Maker of Logos
Useful tip: Other than your usual goo cleaning (soap/water/alcohol) you can also get a big ball of solder going on the tip of the iron (broad flat tip preferred) and wipe the solder around the pads a lot. It will suck up any residual dirt if it's light enough, and then you can discard the extra solder. If you're not using any extra flux and only have a rosin-core solder or something, that also helps to get the area all flux-ed up.

 
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