Pretty basic question but I am struggling to find the words to get the correct search result. The soldering iron I bought came with very narrow tips that I think are supposed to be used for circuit boards and components.
When I attempt to solder lines from a USB cord together the line never gets warm enough.
I remember in the past soldering copper lines together from an appliance with no issue so I don’t think I’m doing anything wrong in terms of technique but who knows?
I suggest that you give details of the iron (and tip) and solder that you are using and a close up photo of the wires that are being problematic.
The iron temperature control may be faulty and the iron just not getting to soldering temperatures. Or you may have it set too low.
The thermal mass of typical USB wires is so low that, if the solder actually melts freely at the tip end when not soldering anything, it should do so when soldering these wires.