Sunday, June 16, 2013

Adapting an Adapter

This has been a very slow-developing post (over a year in the making), so instead of writing some long, clever introduction about power adapters, directed evolution, and survival of the fittest, we'll just give you a set of instructions for how we came to fix Katie's Macbook power adapter, starting from the very beginning.  If you already have a broken adapter or two, you can skip to step eight.

1. Visit someone with a new puppy.  Make sure the puppy's teeth are very sharp.
2. Play with puppy for a while, then sit down on a chair and get out an Apple laptop.  Make sure to keep an eye on the puppy.
3. Blink.
4. When you open your eyes, notice that puppy is chewing on something small.
5. Ask puppy what it has in it's mouth.
6. The puppy will probably respond with something like, "Nom nom nom. Nothing. Nom."
7. Don't believe puppy.  Pry puppy's mouth open with one hand and remove very end of power adapter cord from beneath puppy's tongue.  It should be the magnetic end that attaches to the computer, and not have any extra cord with it.
8. Realize that adapter cannot be satisfactorily repaired and search for replacement online with remaining battery.
9. Become angry and defiant that a replacement adapter costs $80.  Look for better deals.
10.  Find one that's a better deal and order it.  Don't worry too much that it doesn't have the little Apple logo on the white box part.  But keep the old adapter, just in case.
11. Use replacement adapter for about a year, until the plastic on the white box starts to melt enough that it looks like it might self destruct.

Now you have one adapter with a good box and no end, and one adapter with a good end and a dangerous-looking box.  Now we can take the good end and the good box and make a good adapter!
First cut the wire off the bad box and cut the casing off the end 1-2 inches of the inner and 5-6 inches of the outer cables.  As a side note, with this approach, it's possible to gain a few extra feet of cable length on the adapter.
On the original adapter, the cable strands have a silver-colored coating, which evidently needs to be removed for this repair to work.  You can use a knife or other hard object to scrape the silver part off, but the job is much quicker and cleaner with sandpaper.
Also get some heat-shrink tubing from RadioShack or Home Depot.  We got a little assortment box with multiple sizes and colors.  Make sure the pieces are long enough to cover the exposed wires, and put them on one of the cables like so.  The extra piece of cable at the lower left is part of the discarded cable housing trying to sneak into the picture and get his 15 minutes of fame.  It's not the end of the cable being repaired--that should have the magnetic fitting that attaches to the computer on it!
Twist the strands from the two inner wires together like so.  Ignore the fact that the heat shrink tubing is on the other wire and shorter in this picture than the last, because it just means that the first time we did it, we forgot to put the bigger section of heat shrink tubing on.
Solder the two halves together.  Watching the capillary action of the melted solder go into the stranded wire and then solidify is totally awesome.  It's like something from a Terminator movie.  Two side notes here: if you don't have a soldering iron but do have a wood-burning tool, you can still do this step.  Also, be careful not to shrink the heat-shrink tubing while you're soldering, or you'll have to start over.  At least then you'll have another chance to remember to put the bigger piece of heat shrink tubing on before you connect the wires.
Slide the smaller piece of heat shrink tubing across the junction you just soldered and shrink it with Katie's special heat gun she keeps in the bathroom for purposes just like this.
Solder the outside wires together in the same way.
Slide the larger piece of heat shrink tubing across the connection and shrink it.
Step back and admire your work before testing it.  Hey, that looks pretty good!
Feel slightly nervous for the moment of truth.  Plug the adapter in and wait a few seconds to see if the little spot lights up.  Hey, it works!
Wrap it up and pretend like nothing ever happened.  After all, it wasn't like Katie would have had no way to charge her computer if this didn't work or anything.

Have you repaired any of your own power adapters?  How did it turn out?  Tell us about it in the comments section below!

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