Audio wires won't solder - Page 1
Forum section: electronics / repair

author: TomerP
author_rank: Newbie
timestamp: May 28, 2021, 11:40:23 pm
content: Hi, I'm trying to replace a MINI-DIN connector for an Altec Lansing ATP3 speaker. I'm having two problems here:1) The thin wires won't catch on to the solder.2) The MINI-DIN headers themselves melt and deform quickly when the soldering iron is touching the pins attached to them. I've lowered the soldering iron to 260 degrees Celsius, which is supposed to be around the tin's melting point, but this still happens relatively fast.I'd appreciate any tips here!

author: james_s
author_rank: Super Contributor
timestamp: May 29, 2021, 12:45:56 am
content: The wires may not be copper, or the strands may be individually insulated, those wires can be a pain and I'm not sure what do do about that, I suppose you could try crimping on a more easily soldered wire.For the connectors a trick I use is stuff a piece of wet paper towel or cotton ball in the end around the pins, or if the connector design makes that impractical, support it so the end of the connector is submerged in container of water. That will keep the pins cool enough to not melt the plastic, and the thermal conductivity should be low enough that you can still heat up the end you need to solder.

author: dc101
author_rank: Regular Contributor
timestamp: May 29, 2021, 01:04:11 am
content: The bundle of wires look like they're enamel coated. When it's solid wire, I usually use sandpaper, but that wouldn't really work in this case. Not sure what the best way to remove that is.

author: Miti
author_rank: Super Contributor
timestamp: May 29, 2021, 02:43:25 am
content: Aspirin. Find an aspirin pill and heat the wires while pressing them against the pill with the soldering iron. It will strip the enamel in no time. Don’t breathe the fumes.

author: xrunner
author_rank: Super Contributor
timestamp: May 29, 2021, 02:51:49 am
content: Quote from: dc101 on May 29, 2021, 01:04:11 amThey will likely take solder. The coating will burn off if you heat the wires to 350 -370 C for a little while with some solder on your iron. This is by design, so they can be soldered yet remain insulating otherwise.

author: bdunham7
author_rank: Super Contributor
timestamp: May 29, 2021, 03:09:37 am
content: Use a flux pen or some flux gel on the terminals and plenty on the wires.Tin the wires with plenty of solder. Please use leaded, eutectic. (63/37 or the equivalent silver type)Tin the terminals.Hold the wire against the terminal and quickly clamp it with the soldering iron, not adding any solder. As soon as the solder melts, pull the iron away.

author: TomerP
author_rank: Newbie
timestamp: May 29, 2021, 09:44:14 pm
content: Thanks everyone for your great responses. What worked for me is burning the coating off using the solder as xrunner suggested. Then, I tinned the wires and the connector's terminals and just had to bring the two together with the iron for 1 second.Unfortunately (#1), my JCD soldering station decided to die during the process (it was only the second time I've ever used it!!) and I had to complete the soldering using my trusty old 25W Zico soldering iron...Also, (Unfortunately #2) the wiring diagram I had seems to be wrong and after completing this arduous task, the speaker won't turn on, so I'll have to find a correct wiring diagram before I could give it another try.

author: james_s
author_rank: Super Contributor
timestamp: May 30, 2021, 05:00:15 am
content: Do you have the original connector so you could measure it?

author: tooki
author_rank: Super Contributor
timestamp: May 30, 2021, 10:03:18 am
content: Quote from: TomerP on May 28, 2021, 11:40:23 pmCounterintuitively, sometimes, you need a higher heat in these situations, so that you minimize the time to make the joint. A lower temperature can make it take much too long to make the joint. (Of course, tinning the wire and pin separately are the first thing to do.)

author: TomerP
author_rank: Newbie
timestamp: June 01, 2021, 09:11:24 am
content: I do, but the manufacturer cemented it with hot glue, so I'm not sure how I could open it to see what's the wiring is supposed to be like.

author: pitpat
author_rank: Contributor
timestamp: June 01, 2021, 05:20:11 pm
content: A dremel with a cutting wheel would make a great choise for this job.Cut the silver connector with two vertical cut and melt the glue with boiling water.Let us know and don't hurt yoursef in the process

author: jpanhalt
author_rank: Super Contributor
timestamp: June 01, 2021, 05:31:03 pm
content: Quote from: TomerP on June 01, 2021, 09:11:24 amHot melt is easily loosened with isopropyl alcohol. I use something in the 90+% range. I small drop will wick under the hot melt, and it will easily peel off.

author: james_s
author_rank: Super Contributor
timestamp: June 01, 2021, 07:24:11 pm
content: Quote from: TomerP on June 01, 2021, 09:11:24 amWhy do you need to open it up? Can't you just test it with a continuity meter and figure out any broken wires through the process of elimination? Or are ALL of the wires broken? Otherwise just cut the shell and peel it away from the core.

author: TomerP
author_rank: Newbie
timestamp: June 07, 2021, 10:24:04 pm
content: Quote from: james_s on June 01, 2021, 07:24:11 pmYou're actually right about that. I've tested the pins for continuity and seems like my original wiring was correct. Further testing showed two things:1) The metallic part that is wired to ground didn't make proper contact with its counterpart in the socket. After fixing that, the speakers came back to life.2) it seems that I need to cut the cable further, since small movements make the sound get choppy and unclear.This project felt like a quick fix but it proved to be more complicated than I first thought lol