Repairing a MagSafe Charger's Cord

Here is how to repair the cord of Apple MacSafe power adapters.

There are three common failure modes of a magsafe wire:

1. The base of the cord becomes frayed where the wire enters the power brick.  This is usually caused by repeatedly wrapping the cord far too tightly around the brick's "ears".
2. The head of the magsafe connector becomes frayed.  This is usually caused by repeatedly removing the magsafe magnet by yanking on the cord.
3. Chewed up cord.  This is where a pet or other pinching device weakens the cord.

These types of failure are usually repairable at home using the technique described here.

Tools Required:

1. A beginner's Soldering kit, like this one, including a low-wattage soldering iron, rosin-core Solder, and wire strippers.
2. Heat shrink tubing.   Any color works, but these days I use white to repair a MagSafe cord.
3. One Soldering Sleeve, appropriate for 22 or 24 AWG wire
4. Heat gun (optional.)

Process: 

The general process is to (1) repair any broken segments of the cable, (2) use heat shrink tubing to strengthen the cable's weak points, and (3) use heat shrink tubing to protect any repairs.

Step 0: Unplug the adapter from both ends.  Of course.

Step 1. Identify the problem ... and cut the cord

First I need to figure out where the problem is.  Are the ends just fraying but the center of the cord look good?  Great!  Then I will use my wire cutters to cut the cord about 1 foot from the power brick.

If the cord is broken in the middle, then I will use wire cutters to cut the cable and removing the flawed section.

Cut out bad section of the cord

Step 2: Heat Shrink

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, slide another piece of heat shrink all the way to the end and shrink in place.

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!

Additional Tips

I have an alternative approach that works well:

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.