DIY USB cable repair ; challenge accepted.

I will follow up to edno’s hardware laden post (nice one, BTW) with my own brand of DIY tutorial happiness.

NOTA : This is a simple tutorial and by no means THE definitive soldering How-To.  I’m not an expert but the job I did with the oscillating tool, as related here, worked as it was supposed to.  Drop me a line if you have any questions!!

From some of the previous posts that I’ve have written, you are probably aware that I have three mousers at home and when not sleeping on the couch for 18 hours, they prowl around in search of anything laying about.  One of ’em has a predilection for all-things-Apple, specifically, all the white connection cables, which is just about everything Apple distributes.

She chewed through 2 sets of earphones (yes, yes…I stow them away safely now), gnawed on the main cable for the laptop power supply and bit through my USB keyboard cable (pic#1).  Enough dammit, that was a gift and I love that thing… so, I decided to replace the end plug and not junk the keyboard, in this day and age of abject commercialism.

In another life, I was a lighting technician so working with cables, different types of connectors and soldering is not a new ‘thing’ for me but I have never fixed a USB cable.  Time for some research!   USB connectors – the link will bring you to the wiki page and all the info you will need.  All types are identified as well as the pin-out /wire colour, etc.

Now that we have this information, we need parts, supplies and tools arrh!, aarrhh!, aarrhh!…sorry.

Tools (pic #2) – all of which I already had: soldering iron, wire strippers, cutters, hemostats, magnifying glass, heat gun, Helping Hand.

Parts/Supplies – bought from an electronic supply store, here in Montreal  : heat shrink tubing (1/4″ & 1/2″, white, 4$) –  one bag with 2X  USB ‘A’ connectors (6$).  I already had the rosin flux and the soldering tin on hand.

Prepping. – Luckily, the cable was cut about 2 inches from the end connector, so I won’t loose too much of it.

Important : cut a small length of the 1/4″ heat-shrink tubing, say, 1/2 inch or so and slide it over the cable, you will use it at the end of the soldering process.  If you forget, well, it’s not the end of the world but it won’t be as “aesthetic’.

Using sharp wire snips, make a nice clean cut to the tip end of the cable, it will make stripping the insulation easier.  Next, using the stripper, remove about a half-inch of sheathing and separate each wire (pic #3).  You should find 4 wires : Black, red, green, white (sometimes  translucent).  If there is an insulation foil, discard it, we will not be needing for this application.  Next, strip the ends of the wires about  1/8 th  inch, just enough to expose the metallic wire (pic #4).

I also identified where the wires will be soldered to the USB connector (pic #5).  I used a sharpie to write the corresponding wire colour to each rod…you make less mistakes that way!  I used the Wiki info to identify the rod/wire sequences.

Fluxing. – I was taught to flux all parts before the soldering process.  It has always worked for me but methods will differ from one person to the next.

I put a bit of flux on the connection rods and on the tip of the stripped wires.  I usually dunk the wires in the flux can or use the tip of the tin solder to deposit some on the components to be used.  Any oxidation or residue on the parts to be soldered will be ‘cleaned off’ and won’t hinder the bond.  It will also help the capillary action of the solder between the components.

Soldering. – Now the fun begins!

Plug the soldering iron and let it heat up.  Once it’s hot enough to steam out the water in a damp sponge (usually kept in the little receptacle in the base of the iron (pic #2) roll the iron on the sponge to clean off the old solder.  Give it a few seconds to come back to full heat and apply a thin layer of tin around the tip.  This is critical because it will make soldering easier and faster.  Components are sensitive to heat; the faster you can get them to bond, the less likely they are to get damaged.  It will also prolong the life of the iron.

Heat the wire using the iron and apply the tin directly to it and the iron’s tip.  It will melt and coalesce with the wire.  Using the same method, heat the rods on the connector and apply the tin, just enough to cover the rods – don’t leave the heat on them too long (pic #6).   Use the magnifying glass to verify your work.

Now it’s just a matter of soldering the wires to the rods.  Apply the iron to the rod and the wire at the same time, the tin will melt and bond both parts together.  Make sure that a ‘bubble’ of tin forms on the bond, that way, you are sure both parts are well soldered together (pics #7-8).  Use the hemostats to work the wires…it’s more precise and you won’t burn the tip of your fingers!!  Don’t forget, if you notice slag on the iron, clean it off and re-tin the tip.

Assembly. – The hard part is done.

Now all you need to do is assemble the connector.  Place the soldered rod board in the chassis (it has a stopper at the end so don’t brute-force all the way! pic#9).

Test the connector by inserting it in one of the USB ports of your machine.  Everything should work.  If not, verify your soldering, maybe one of the wires hasn’t properly bonded.

Place the black protection cover on top of the wires; make sure they are neatly separated.  It will snap into place and once in, you won’t be able to remove it without damage, so make sure it’s properly aligned (pics#10-11).  On top of the protector, snap the metal casing into place; it has notches on the sides so you might want to squeeze the casing to click it in (pics#12-13-14).  Finish it off by wrapping the securing forks around the cable but don’t over do it or you’ll cut the cable…and have to start all over again!(pic#15).  Remember that length of tubing, use the heat gun to shrink it around the forks, for aesthetics more than anything.  You can also finish the job by inserting a piece of 1/2 inch shrink tubing over the chassis  to covert up the metal but that’s up to you(pic#16).

Re-test your connection.  In theory, everything should work (pic#17).

Hope this was helpful.  Have fun working on this and remember…it’s a DIY project, not your Life’s work so go easy on yourself!

As this was the 501st post on this site, being the geeks that we are, I have to point out that it’s a Star Wars reference in itself!!

All hail Vader’s Fist!  We are Legion!


  1. Fantastic article! Be ry impressed, the end result looks great. Next time I need something soldered, I will call you actually I have a wireless USB dongle to get fixed similar to this, maybe you would like the challenge?

    Loved the Tim Allen reference!

  2. Sorry, just found out that the edit function doesn’t work from my iPad, too bad, it would have been easier to read Very impressed instead of Be ry impressed…