2018-01-22

Repairing a MagSafe Charger's Cord

Apple MacSafe power adapters can get a lot of use, and their cords are quite robust.  But they do fail, leading to no function or poor reliability.

Cats chew on the wire.  They get wound tightly very often.  They get yanked and tripped over.  And they get pinched by doors and furniture.

All this abuse can ruin the MagSafe cable.  The power brick itself is usually fine, but the cord needs repairing.

In this article, I show how you how I mend a MagSafe cord.  At the bottom, I've added an alternative procedure.

Tools Required:

  1. A Soldering Iron kit, like this one, including a low-wattage soldering iron, rosin-core Solder, and wire strippers
  2. Heat shrink tubing
  3. One Soldering Sleeve, appropriate for 22 or 24 AWG wire
  4. Heat gun (optional)

Process:

1. Using wire cutters, cut the cable, removing the flawed section.  The flawed area might be obvious due to a tear or a bite mark.  Or perhaps just the ends are starting to fray.  In that case, I still have to cut the cord.
Cut out bad section of the cord

2. Slide a roughly 2 inch piece of heat shrink tubing over one of the wires.  It should be pushed down far away from the end of the cable that is being worked on in order to prevent it from shrinking too early.  If the ends are starting to weaken and fray, use heat shrink to repair.


Slide on heat shrink tube

3. On each end, strip about 1 inch off of the outer plastic coating of the outer wire
4. Twist the metal wires together, revealing the internal wire.


The outer sheathing is twisted on both ends

5. Strip about a quarter inch of the insulation off of the inner wire.
6. Twist together the external wires.

The external sheathing is rejoined by twisting. The inner wires are striped
7. Solder the external sheathing together.
8. Allow work to cool (about 5 minutes) 
External sheathing is soldered together

9. Stick solder sleeve into place in order to join inner wire.  Trim solder sleeve as necessary.
Solder Sleeve
Solder Sleeve, trimmed and placed over joint

9. Heat solder sleeve until its internal solder melts and the sleeve shrinks tight.
10. Allow for work to cool (about 5 minutes)

Activated Solder Sleeve


11. Slide heat shrink tube over exposed "wound"
Heat shrink tube over wound

12. Shrink tubing with heat source.

13. Test.  Success!

Modified Procedure

I have since modified my procedure to make a smaller, prettier, stronger repair. My new procedure:
  1. Original steps (step 1 through 5) are the same.
  2. Then, use a solder sleeve for the inner wire (step 9).  Let cool.
  3. Bind the outer cable with some wire wrap wire and then solder.  Let cool.
  4. Apply shrink tubing over cut (step 11-13).  Use white heat shrink tube.
This process results in a slightly smaller repair area, and seems stronger too.









No comments:

The Price of Electricity

I'm sitting at home here looking at my electric bill.  My bill says that electricity costs 21¢ per KWH.  But that's not true. The ...