Repair a Powerbook AC Adapter




Introduction: Repair a Powerbook AC Adapter

The cord coming out of my Powerbook AC adapter shorted out. Eventually, it even sparked and started to smoke. After this happened, having nothing to lose, I ripped it apart and made it work again. This is the story.

Step 1: The Problem

This explains how to fix an Apple Powerbook AC adapter that has a shorting cord. If your power adapter has a different problem, there might still be useful information here for you.

Step 2: Chop It

Since the cord is shorting, we ultimately want to cut out the place where the short is and splice the good parts back together. Go ahead and chop the cable off now as it will just get in the way if you have to open the case.

The short in my adapter was so close to the point where the cord enters the casing that I needed to open up the case to get to the length of good cord inside. Apple doesn't expect these cases to be opened and, as such, they super-glued them shut. This makes opening them a real pain.

Step 3: Get Inside

Now comes the hard part: getting the case open. I've seen suggestions of using a small screwdriver and a hammer. This might work fairly well to crack the seal. I didn't have a hammer, so I sawed away at the seam for a while and then pried around with a screwdriver. Experiment, pry, bend. Just get the seal around the outside cracked.

Once the seal is cracked, you still aren't quite home free because there's a metal shield inside that's glued to the top of the case. If you're pulling and it springs a little bit but doesn't open, get up under the shield with a screwdriver and gently separate it from the top. You can see the shield in image 2, below.

Step 4: Expose Some Wire

The power cord itself isn't your standard two-wire cable. Instead, it's a very thin coaxial setup. The core provides the ground and the outer cage acts as a ground. In order to splice these, we first need to separate them.

Start by carefully stripping off the outer casing. Wire strippers could work here, but be careful not to cut through the ground wires. I didn't have a wire stripper, so I used a knife and my fingernails. Once the outer casing is off, separate the ground wires and strip the casing from the inner cable. There will be some thin green floss mixed in to the ground cage that provides padding and strength to the cable that you can separate out and trim off.

Now we need to get a some exposed wire on the adapter side to splice the cord on to. See that little plastic thing that the cord passes through as it enters the case? It keeps the cord from getting yanked off of the board when you pull on it. Inside the plastic thing, the cord is tied in a knot. If you can cut away the plastic thing without cutting through the cable, you can untie the knot and get a decent length of wire to work with. As you can see in the second photo, I couldn't, but it worked out anyway.

Once you have the cord exposed, repeat the stripping process from earlier and splice away. To do this properly, you should probably twist the wires and then bind them with solder. I didn't feel like getting out my soldering iron so I just wrapped them with electrical tape.

Step 5: Wrap It Up

It's time to wrap things back up. Before you start reassembly, it's probably a good idea to test out your wiring to make sure it works.

When you're putting things together, wrap the cable in such a way as to protect both the splice point and the board connection from stress. You don't want all of your hard work to be undone by a careless yank on your cord.

Once you've got everything pretty secured the way you want it, tape it up (or glue it, or encase the whole thing in carbonite).



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    22 Discussions

    Thanks for posting this. Even 5 years later, it is still relevant. I had a rip in the cable itself and was able to splice and solder the cable back together. Thanks!

    the adapter i was trying to fix still dos not work, I tested it but still i haven't had any reading... what could the problem be? please help..

    It was going to happen one day - despite me never using the 'winding wings' but instead looping around the whole transformer making sure the first loop was loose. It's a weak point but it's not just Apple PSUs that suffer from this.

    I even managed to keep the strain relief grommet by peeling back the rubber covering the knot then sliding it a few inches along the cable. Yay!

    Incidentally, I was happy to find string inside the cable. I'm assuming it was kevlar because my scissors didn't know what to do with it ;)

    Thanks for posting.

    I had exactly the same problem, the wire sparked and started to smoke near the box. I opened it with knife and hammer (It was like glued together or something!) and carefully did the procedures with the wire. But my adapter refused to work again. Could it be that the wires went wrong inside the box on the circuit board? Is it this way: at the edge of the board you should solder the ground (the "hair" that is around the grey wire), and the grey wire should go more inside on the circuit board? I did this and it did not work again (no light at the other end of the chord). Now I don´t know what to do? Should I use a multimeter to check out something? Please tell how to do it. At least the power chord is okay (it is a separate one, and I took it from my portable radio that had a similar, working one), but no power is coming to the computer and my battery is running low (now only 40% left).

    This was wonderful!!!  I am a grad student and my ac adapter finally stopped working at 4 this morning while I was working on a project.  The short was near the plug in at the laptop, but these instructions still worked.  I don't have any electrical tape with me, but I used scotch tape to work until I get back home.  It is working fine!!!  You saved me about 65 dollars.  Thank you so much!!!

    You could have been more respectuous of Jonathan wills by using a white tape :)

    I had the same problem today !

    My tip:
    Use a hacksaw to  open the adapter (if you have one!)

    thanx a lot for the instructable, it helped :)
    My sister had the same problem with her powerbook g4 adapter. I contacted apple dealers here and they asked a stupid 150$ and 20 days to get me the adapter :O...this was stealing (they said that the powerbook is old and they do not have it's replacements), plus, 20 days was like impossible, cuz my sister has work and she uses her powerbook all the time...
    Well, as google is my friend, and is my other friend, i managed to fix it and she's up and running again :)
    thank you from all my heart for this...respect ;)

    Mine also died. but I think it was because my cat ate the cord. This still may help me to fix it and keep a backup. I have more cords that my cat has eaten. bummer, too many of them... and I can't fix them all. thanks!

    I find that hitting sealed transformer casings fairly hard multiple times along the seams can open them soon enough to gain access to the guts, or if you're not bothered about salvaging the casing (either component harvesting or have a project box replacement on standby), just crush the case in a vice until it pops apart... :)

    Unbelievable!.. All of a sudden my girlfriend's power adapter stopped working, and I immediately went to Google for help... I searched for "fixing apple powerbook power adapter" and ended up at this link in this amazing website that is Anyway, we had already chopped off the cable and tried making it work on our own, making use of our own "Macgiver" qualities. Nothing happened, so we decided to try whatever, since she really needed to make her laptop work so she could work... We followed the instructions, step by step, we sawed the adapter, she even sliced her thumb in the process, so, be careful if you try it, 'cause I never imagined these things were so definately sealed forever!.. After opening the adapet and splicing the cables, connecting it all together and wrapping the adapter with tape, she immediately plugged it in, and guess what?!. The power adapter's power light actually lit up! Yes, it worked!!! This whole site is amazing, this instruction link for the adapter is great and detailed, even though I never got to understand why it made any difference having to open the adapter, since we didn't actually get around doing anything in there... So, try connecting the cables thoroughly and the best way possible before opening the adapter, 'cause it is a real ordeal. Anyway, gotta get back to work now!.. ;)

    I had a short at the computer-side of the power-adapter. My local Apple store gave me a free 85 Watt power-adapter. When that didn't work they replaced my logic board, DVD/Superdrive & power harness all for free. My wife found out Apple was having a -- Uh-Hmm, err -- "issue" with these power-adapters and quietly replacing them (That's why I took to the Apple store). It's on the Apple site, but you have to dig (sorry I don't have the URL). Just a word of caution for DIYers -- Have good commercial soldering iron with a needle-point tip and a good Solder-sucker. My Solder-sucker worked great, but my $10 Radio-Shack soldering iron was inadequate.

    Came across your site by chance and what a relief i did, awesome job, what a great idea and great service to offer people who dont want to keep buying expensive cables (as much as i love Apple they do change up the ying yang) tired your advice and worked first time, this is the 3rd cable i have had Great job, thank you. Kris

    Thanks guy. What a relief to have repaired the power adapter on my Toshiba laptop. Your instrutions are great. I needed to splice both the wire and the sheathing though, else got no power. Thanks for sharing.

    amazing - thank you so much. costed me $8 for soldering wire and electrical tape! vs $80 - totally dope... i heard on another site: apple will replace this adaptor (even if your computer is out of warranty) if you say it started smoking. I was gonna do this, but then i thought "REDUCE, RECYCLE, REUSE"! this solution is definitely easier on mother earth.

    Geat web page. We have 4 plyful kitties. I repaied the power adaptor cord to my G4 powerbook using the instructions provided. Saved ~$80. Thanks! I used an exacto knife to free the wires. One protected bundle was surrounded by the other wires (hence coaxial?). I teased the bundle out and slit the length of very tough covering to relase the wires. These are hard to see and may not be obvious to neophytes like myself. Given your webpage, I placed the entire cord lengthwise bewteen long strips of electrical tape, hoping to prevent twisting and tears, ect. Thanks again.

    Mine shorted out as well X_x Wonder If I can make this work? Thanks!

    You know mine shorted out in the exact same place. I wonder how many of these this has happened to? I fixed mine almost the same way except I just soldered it right to the pcb and used wire ties for strain relief. mine got way to hot wraped in electrical tape. when it eventualy shorted out at the other end I ditched it and rewired the "yo-yo" power supply from my old powerbook(G3) to work with my iBook(G4).


    11 years ago

    Ditto LasVegas's comment on using a vice. If you notice your cable just STARTING to fray near the exit from the wart, you can tape it to the wart early as a sort of additional strain relief. I've got a mac supply around here "fixed" like that; I'll see if I can get a picture...