Daniele Verducci 🧉
Reparing the Fabula. The speaker and battery cables were broken at the soldering point. No idea why. Also, it isn't the first time it happens. They are common Dupont cables cut and soldered (because I need the connector on the other end). They shouldn't be subject to mechanic stress, it seems more like a chimical/oxidation problem... but I have no clue at all...

#electronics #repair #workbench #lab #soldering #opensourcehardware
May 13 at 11:01pmWeb
Show threadBob Beaker1d ago

@penguin86 At the risk of teaching grandma...

You are aware that flux used in soldering, whether applied separately or as part of the solder medium is an acid? It's an essential part of the soldering process but should be removed after soldering. Any residual flux will slowly eat away at the joint especially around any imperfections.

I use IPA and a stiff brush to remove flux residue.

No clean fluxes are available but not usually at the DIY level.

Show threadDaniele Verducci 🧉1d ago
@bbeaker good point! I use a lot of flux, and usually clean the residues with IPA, expecially when I solder to a PCB. I may have not done the same with these joints... but I didn't change anything in the way I work (even still using same solder and flux) and this didn't happen in the past. Maybe this cables are just too thin...
Show threadBob Beaker1d ago
@penguin86 The other thing that just sprung to mind if the wires are of unknown origin. Copper covered aluminium?
Show threadDaniele Verducci 🧉1d ago
@bbeaker oh, that's probable. They appear copper-colored, but the price was low, so they may very well be aluminium...
Show threadJustDude 🙋🏻‍♂️🫶🏼🕊️1d ago
@penguin86 Dupont cables are not the best wires to solder, as far as I experiencing. The do not solder great and break easily with friction at the solder joints
Show threadDaniele Verducci 🧉1d ago
@justdude yeah, i'll probably need to learn crimping the connectors myself...
Show threadJustDude 🙋🏻‍♂️🫶🏼🕊️1d ago
@penguin86 Or buy a box of colored wires silicon outlayer.
Show threadJmp491d ago
@penguin86 if there's any vibration on those wires (and they lead to a speaker) the stiff point of the system is the part of the wire with the solder infused on it. So that's the likely failure point.
I crimp jst-xh's for this, specifically that size because I have a big selection box of them assorted, and dont have dupont crimpers or ends.
Also very guilty of the crime of just pushing the wire through a pad and soldering it when space is tight, but this is prone to this failure too.