1 post tagged “apple power brick failure broken coil cables”

Most apple laptop power supplies since the iBook have some sort of cable management / warping device built into the brick itself. Although this appears to be a "insanely great" innovation, it encourages poor cable husbandry and premature power supply failure; thus requiring one to fork over $80 for a new power supply. There are two main causes of cable failure, kinking and twisting; when these two are compounded a thin power supply cable can't hold out very long even if it were made of the very best materials. Therefore, proper cable care will help extend the life of your power supply.

Kinking:
Cables are challenged with the fact that in order to carry electrons one must use some form of metal, and any flexible metal will break if flexed enough times at the same place.

Twisting:
Twisting in the cable can also introduce unnecessarily stress since the individual strands of wire get twisted then stretched when tugged on causing breakage, the physics is the same as wringing out a towel by twisting and pulling.

Now think about what happens when someone grabs one of those apple power bricks, stretches the cable around one cable management "wing", making sure it is pulled nice and tight, and then proceeds to TIGHTLY WIND the rest of the cable onto the wings as if it were a spool of fishing line. This is about the WORST thing you can do for the life of your power supply, it kinks the cord where it exits the power brick, puts a new twist into it with each wind around while at the same time adding tension to the cable.

Here is a example of what not to do:

To prevent this from happening the over-under method of cable coiling should be used. This is what I do, lefties may reverse hands.

How to prevent Apple power supply cable failure:

1) Rest the power brick on a solid surface for support, like a desk or your lap.
2) Grasp the cable near the power brick with your left hand.

3) Then with your right hand make a loop about the size of a cd, lay the overlapping cable into your left hand.

4) Next grasp a section of loose cable a few inches out from your left hand.

5) Now flip your hand, tucking the loose end of the cord underneath the fixed section between your left and right hands.
6) Lay the tucked in portion into your left hand.
7) Now repeat steps 3-6 for the remainder of the cable length.

I simply lay the coil on top of the power brick and stash into my waterfield cableguy organizer pouch.

You may experiment with loop sizes to find one that works for you, I like to try and keep the loop size roughly the same size as the largest face of the power brick. Just in case my instructions were not clear here is another tutorial.