Introduction: INTEG 375 - Fixed-Up Macbook Charger
As someone still working with a Mid-2010 MacBook Pro, I was loath to invest in a new charger when mine stopped charging my computer. The wire had frayed where it connected to the charging brick (who knew that the metal wrapped around the interior plastic sheath was more than just a structural element?) and I was left scrambling.
Unfortunately, I did end up getting a new charger since so few people had one of the old MagSafes to share with me. I was sure, however, that the old charger was not going to go in the garbage. I have always liked to collect things, and so returning this piece of tech to working order just made sense to me. As well, I was worried about endangering my new charger my keeping it in my backpack along with books, papers, and a computer (which contributed to the degradation of the old charger). I even started taking the new charger to school in a plastic container, which was a good solution, but didn't feel permanent.
During a Fix-It style class, I have been working on making my broken charger work again, learning new skills and taking some risks that I would usually be loath to take.
What I needed for this project:
- Pliers/Wire Cutters
- Soldering Iron (And some solder)
- Heat-Shrink Tubing
- A way to test connectivity so I didn't short my computer!
This Instructable was prepared as a project for the Fall 2018 offering of
INTEG 375: Hands-on Sustainability, a third-year course in the Knowledge Integration program at the University of Waterloo.
Step 1: Diagnosing My Problem
If I'm being honest, I had no idea that the metal wire inside of the rubber cover on my MacBook Pro charger was anything more than structural support. It turns out that that wire is actually an important piece, carrying current back from the MacBook to the charging brick and completing the circuit.
Once I realized that the braided metal wire being fully frayed off at the connection was my issue, I was able to move forward and begin working on the actual fix. My first quick step was to disconnect the rubber clip piece (Image 3) because it was exacerbating the fraying at the charging end of the charger.
Skills for this Step:
- Using an exacto-knife to cut through the rubber clip
Step 2: Opening the Case
Apple designs and builds its charger brick cases so that they are not easily openable and resealable. I started the process of opening the case by taking an exacto-knife to the seams. I realized that this didn't feel too effective, since I wasn't cutting all the way through the plastic. Though I could have switched to a heavier knife, I ended up just moving forward to using pliers to push out the sides of the case.
First I had to apply some pushing power to pop out the cord-wrapping flaps (which were the things that caused this problem in the first place). Then I could better position the pliers and put a real push in on each side. I didn't want to break the case, but I had to use a bit more strength than I felt comfortable with. By pushing out along the edges with the pliers, I got the case apart without too much damage. Putting the case pieces aside, I could then focus on the interior.
Skills for this Step:
- Being able to use the pliers with finesse to make sure that it was enough pressure to pop the case open without totally breaking it
Step 3: Taking Off the Wire
My next task was to take the wire off of the case. I wanted to open up the interior a bit more to see how things were arranged, and so I peeled back some of the 3M tape and bent the copper pieces away from the circuit board.
After the rubber connector which the wire went through, there was a black and a white wire soldered to the circuit board. I decided the best thing to do would be to snip the wire before the rubber connector, and then deal with those white and black wires by unsoldering them in order to keep the rubber connector stable.
I grabbed a pair of wire-cutting pliers and made the cut right at the connector. I then stripped the rubber off the charger wire to give myself some space to twist the metal piece tightly.
Skills for this Step:
- Wire Cutting with Pliers
- Wire stripping with an exacto-knife
Step 4: Unsoldering
I marked the spot where the black wire was soldered on using a black sharpie, so that I would not forget which wire went where. Now, I had to learn how to solder! Using a soldering gun, I attempted to take off the wires, but was pretty unsuccessful.
All I was doing was adding more solder to the spots. After a lot of floundering, and watching some YouTube videos about soldering, I turned to the class professor (who's soldering gun it was) for help. It turns out that the soldering coil needed to be tightened, because the tool heats up in part based on how solid the connection is of soldering coil to the gun itself.
After it was tightened, my professor and I unsoldered the two wires quickly and efficiently. It was another case of me being unsure how much force exactly what needed. I didn't feel instantly comfortable working with so much heat, molten metal, and no hand protection!
In the end, I didn't do much of the soldering on this step, but I gained confidence and was able to help others with the soldering elements of their projects in our class. I feel like I learned the skill and can now apply it in a range of situations.
Skills for this Step:
- Unsoldering with a soldering gun
Step 5: Cleaning Up the Connector
After pulling the wires out of the rubber connector, I was left with a bit of a mess. Individual filaments of wire were stuck in the connector. They were tough to reach without destroying the connector itself. I first attempted to use a pair of pliers to grab the pieces and pull them out, but I found myself struggling because they would break in the middle, leaving a harder-to-reach piece to be extracted. I went down to a smaller piece of pliers, but that still wasn't enough.
Eventually, I used a larger screwdriver to almost 'drill' into the connector, but the two exits opposite the rubber piece were in my way. With some consultation, and assurances that things would end up alright, the professor had me drilling through the connector exits. One side was easy enough, and I was able to clear it of any remaining bits of wire. The other side, which was even tougher to stick my disconnected wires back through, was too tough.
Using a larger drill-bit, I drilled one whole combining the two exits, getting through a metal piece that was blocking the more difficult one. Drilling left a bit of a rubbery mess, so I pulled my shirt over my nose and drilled over the garbage can. Left with easy access through the rubber connector, I was ready to move on to connecting the wires.
Skills for this Step:
- Patience with the pliers
- Drilling a hole through rubber and metal
Step 6: Making Sure Things Are Safe
First I took the loose metal wire and made sure that it was tight, and that I had cut it back to the spots where it was breaking, to maintain the gauge of the wire. Once I made sure that the exposed metal wire and the covered wire were the same length, it was time for some heat-shrink tubing! This stuff gave structural integrity and protection from shorting/electrocution.
I put on a few pieces to the end of my charger, where it attaches to the computer. I also put a piece over the top of the rubber connector to give that connection more support and distribute the stress further. Lastly, I added smaller gauge heat-shrink tubing to the exposed metal wire, and prepared to solder it to the circuit board. To get the heat-shrink tubing to tighten, I had to hold a lighter over it at a close-but-not-too-close distance, since it burns easily. This required a bit of accuracy and patience.
Skills for this step:
- Using a lighter to shrink heat-shrink tubing without burning it
Step 7: Soldering to the Board
This step was probably the toughest for me. A lot of dexterity was necessary to get the ends of my wires into the correct spots and solder them in place without getting solder on anything else in the circuit board. I kept unwinding the end of the wire when I tried to get it into the hole, forcing me to twist it back together over and over again. Finally, with some finessing, I fit the wires into both holes, and got ready to solder.
Using a soldering iron, instead of a soldering gun like the last time, I got more precision. I was so much more confidant with my soldering after getting help on the last solder, and helping someone else with their soldering between the last soldering step and this one. The heat was also more consistent with the iron. I just had to quickly touch the solder and the iron to the wire. Two clean solders later (and no burns to speak of) I was almost ready to charge my computer.
Skills for this Step:
- Soldering (confidence helps too)
- Patience with the wires (I got frustrated while trying to fit them in, but kept at it and figured it out)
Step 8: Testing the Continuity
To make sure that my charger would not short circuit my computer and damage anything, I made sure to test its continuity with a multimeter. Using a resource like Wikipedia's "MagSafe" page (https://en.wikipedia.org/wiki/MagSafe#Pinout) would help to clarify which pins exactly it was that I needed to check, but instead, my professor and I figured it out together.
We checked the continuity from each pin of the MagSafe to the two pins that go into a wall outlet. Finding that the centre pin was not connected to the rest of the charger, we guessed that it was controlling the light (we were right). The outer pins are ground, and we found continuity with the ground pin for the outlet. The two larger middle pins supply power, and we also found continuity without issue.
Determining that nothing was going to damage the computer, we attempted a charge and used the 3rd party application Battery Health to determine the charging voltage. It gave us a reading consistent with a new MagSafe charger (11.81V) and I moved on to the last step.
Step 9: Putting It Back Together
The last thing to do was get the case back on the charger. Thankfully, I had split it relatively cleanly and it wasn't going to be too difficult to fit into itself. Still though, I needed help to hold the cord-wrapping flaps and their related springs in place as I slid the top of the case on. Once I had it together, I used blue electrical tape (giving it a somewhat Finnish look that I was not intending) to hold everything in place.
I have found the tape to be strong and durable so far, so I recommend some kind of electrical tape. Tape also has the added advantage of being temporary, just in case any other problems arise. Hot glue was recommended to me, but I thought it would be far more difficult to remove if the wire were to get damaged again.
Step 10: Other Projects
While I was working on the charger, as well as before and after, I took on a couple of other projects.
1. My Bluetooth chip has its plastic cast split in half. I used clear nail polish to 'glue' it back together.
2. My professor found an old, wobbly globe that I cleaned up and made not-wobbly. By hammering out the pins, I was able to clean the globe quite vigorously with paper towels, water, soap, and a magic eraser. Unfortunately, I could not get all of the cigarette stains out of the paper. After trying to use an antiquing glaze to even out the colour and different paints to fill in cracks, I decided that the stained colour looked better than my interventions.
I glued up the poles, where the paper was coming loose and allowing the globe to wobble. I also tightened up the screws keeping the base stable. Adding a few washers to the areas where the poles went through the globe made the spin much smoother, and was the final step before putting everything back together again.
3. My watch's minute hand was running into the '4' marker on the face. I opened up the back of it and realized that to get at the face, I would have to remove the crown. Using some watchmaking tools, together with my professor, I learned how to remove the crown. We bent the arm into place and put everything back together. We had bent the arm too far though, and it was colliding with the second hand. I had to go back through the process to bend the arm back down.