TweetFollow Us on Twitter

"Yoyo" Power Supply Repair

Volume Number: 20 (2004)
Issue Number: 5
Column Tag: Programming

"Yoyo" Power Supply Repair

by the MacTech Magazine Editorial Staff

How one goes about writing for the magazine


Apple's award-winning industrial design is world-renowned. One of the most eye-catching devices introduced with the original iBook was the so-called "Yo-yo" power adapter. Sleek and compact, it unfortunately came with a flaw; the vulnerability of the cable near where it connects to the computer. After repeated flexing (from 6 months to over a year) the braided ground portion becomes frayed and detaches inside the clear insulation. This leads to intermittent connections, then complete failure. We have experienced four of these failures, on my wife's iBook/300 and my Pismo/400. The first one was replaced under AppleCare, but the rest would require replacement at $65 each. (Used ones on eBay might be found for $35-$50).

After several months of being out-of-work (common these days for a high-tech software professional in Silicon Valley) and sharing our one functional unit between the two laptops, I finally took a look at the two broken ones we had left and decided to do a little surgery. What could go wrong? The result, after about 1.5-2 hours of careful work, is a functioning power adaptor. It's not pretty, but it should function for a while. I'd like to share the repair process.

Required Tools

Soldering iron and solder (electronic/rosin core); several pliers (slip-joint and needle-nose); an X-acto hobby knife with pointed blade; RTV silicon sealant; electrical tape and shrink-fit tubing; very steady hands and a keen eye doing close-up work. (I once worked as a professional jeweler, and have had much experience doing electrical work. YMMV..). One additional tool is a "third-hand," ( a hobby/craft device with clips to hold your work while you solder.


The first stage is disassembling your adaptor. You need to first cut away the clear covering on the connector; carefully cut lengthwise along the top side (away from the nub that fastens the cable end to the housing). Then cut around the connector so you can separate this piece into two sections; one will slip off the end of the connector, the other will slide back along the cable away from the end. Put these pieces aside so that they may be reassembled later. (Figure 1)

Figure 1. Initial stage of disassembly

(I apologize for not showing earlier stages of the disassembly; the idea to write the article occurred at this stage of the project).

Connector Surgery

Once you have the covering off, you will find a metal slug through which the cable threads. Pull this back to expose the tail end of the connector shell itself. Before disassembling the shell, you will need to de-solder the grounding resistor (Figure 2).

Figure 2. De-solder resistor from connector end before pulling apart

Now that you have the resistor de-soldered, bend the lead back carefully so that the connector end may be detached from the connector itself. A slight tap may be needed to separate the parts. Now the area where most of the work happens is exposed. (Figure 3).

Figure 3. Connector innards exposed.

Here you will need to cut away all the clear "potting" material so that the wires may be de-soldered from the connector. Carefully cutting into the material with your X-acto knife, you may chip the material free from the connector while taking care to NOT slice into the resistor. This one piece needs to be intact when re-assembling your power-supply cable.

After you have cleaned out all the potting material (Figure 4), you will be able to de-solder the wires from the old (broken) end of the cable.

Figure 4. Connector innards un-potted.

Here is where the "third-hand" becomes a valued tool; you need to hold the soldering iron in one hand, have a tool in another hand to pull the wire free (tweezers or a metal pointed tool) and be able to hold the work being de-soldered so that you don't get burned.


Now that you have removed the old wire from the connector, we can deal with the broken end of the cable to be reused. Before going further, you will have to thread back onto the cable the external parts of the assembly that were initially cut free. (You did cut them free carefully so they could be reused, and did not throw them out, right?) Make sure they go back in the order shown in Figure 5. (Additional note: one piece in the illustration did not belong; I had to remove it later. It is the piece with the "nub" that holds the cable end to the housing you wind the cord into). At this time you should also thread onto the cable a 1.5-inch segment of shrink-tubing which will later be used to protect the braided ground shielding.

Figure 5. Re-assembling the shell begins...

Now that you have threaded those parts onto the cable, you need to prepare the end for re-soldering. Cut the end clean where the cable had gotten frayed, then strip back about two inches of the outside insulation. Carefully push about an inch of the braided ground layer back from the end, and twist it off to the side (Figure 6). Twist up about 1/2 inch of the braiding and lightly "tin" the end with solder (this will help to attach it to the connector). Twist up 1/4 inch of the inner conductor and "tin" the end.

Figure 6. Preparing the end for soldering.

Now you should slip a 1/2-inch section of shrink-tubing over the inner conductor; then you are ready to attach the end to the forward-section of the connector, where it was attached before (Figure 7).

Figure 7. Reattach center conductor.

The tricky bit comes next. You will need to solder both the braided ground and one end of the resistor to the middle segment. (My apologies for not including a photo of this step).

Now that the ends are connected, you may begin to reassemble the shell. Slip the long tube over the end of the connector innards; there is one "right" way it goes on. You will see evenly spaced rectangular indentations on the end where the tip protrudes. And the tip should protrude about 1/8 inch beyond the end of the tube (Figure 8).

Figure 8. Assemble connector.

Before you fit the inner end of the inside portion over the end tube, you will be repotting the soldered area with silicon seal (Figure 9). You should also take care that the tail of the resistor is threaded out the end of the cap back toward the cable; you will need to solder it onto the outside of the shell after reassembly.

Figure 9. Example of RTV (Room Temperature Vulcanizing) silicon seal

Squeeze a small amount into the end of the tube and a little into the inner cap; then using a flat tool, pack the material into both ends of the connector. Slip the cap onto the tube and carefully, while holding the tube end with pliers, press-fit the cap onto the tube (Figure 10). You will see some of the sealant ooze out; this can be cleaned off later.

Figure 10. Press-fit cap onto tube after packing with silicon seal.

Let this assembly cure for a while, and get a cup of coffee. After it has cured, carefully bend the tail of the resistor back over the metal tip and solder it to the shell. (Refer to Figure 2).

Now you can slip the gray metal piece onto the end of the connector, and then slip the outer plastic section over the metal slug. Now slide the portion of the cover with the nub over the end of the connector, as shown in Figure 11.

Figure 11. Reassembly of outer cover.

When the segments of the shell covering are pressed together, you can complete the repair by wrapping in electrical tape. Start at the very end and work toward the cable. Keep the tape tight as you go, as the tape will be a structural member of the assembly; it will serve to keep the shell together and provide shielding to the exposed section of braided ground.


Now that you have completed reassembly, the moment of reckoning is at hand. Plug your power cord into the yoyo housing, and then into the wall socket. Now attach the repaired cable connector to your iBook or PowerBook. If your laptop is powered on and booted up, you should see the battery/power indicator showing it is charging/plugged in. Congratulations! You're an electronics repair technician!

The author of this article has been working with computers for far longer than he would like to admit, and on Macs since late 1984. His wife, two grown children, both parents, and both (older & younger) sisters are all Mac owners as well. When NOT working or playing with their Macs, Mark and his wife enjoy the company of three Yorkshire Terriers, three cats, and five cockatiels. You can reach him at


Community Search:
MacTech Search:

Software Updates via MacUpdate

OmniPlan 3.0 - Robust project management...
With OmniPlan, you can create logical, manageable project plans with Gantt charts, schedules, summaries, milestones, and critical paths. Break down the tasks needed to make your project a success,... Read more
Yummy FTP 1.11 - FTP/SFTP/FTPS client fo...
Yummy FTP is an FTP + SFTP + FTPS file transfer client which focuses on speed, reliability and productivity. Whether you need to transfer a few files or a few thousand, schedule automatic backups, or... Read more
Tweetbot 2.1 - Popular Twitter client. (...
Tweetbot is a full-featured OS X Twitter client with a lot of personality. Whether it's the meticulously-crafted interface, sounds and animation, or features like multiple timelines and column views... Read more
MacPilot 8.0 - Enable over 1,200 hidden...
MacPilot gives you the power of UNIX and the simplicity of Macintosh, which means a phenomenal amount of untapped power in your hands! Use MacPilot to unlock over 1,200 features, and access them all... Read more
Typinator 6.7 - Speedy and reliable text...
Typinator turbo-charges your typing productivity. Type a little. Typinator does the rest. We've all faced projects that require repetitive typing tasks. With Typinator, you can store commonly used... Read more
Adobe Lightroom 6.2 - Import, develop, a...
Adobe Lightroom is available as part of Adobe Creative Cloud for as little as $9.99/month bundled with Photoshop CC as part of the photography package. Lightroom 6 is also available for purchase as a... Read more
ForeverSave 2.1.4 - Universal auto-save...
ForeverSave auto-saves all documents you're working on while simultaneously doing backup versioning in the background. Lost data can be quickly restored at any time. Losing data, caused by... Read more
VueScan 9.5.27 - Scanner software with a...
VueScan is a scanning program that works with most high-quality flatbed and film scanners to produce scans that have excellent color fidelity and color balance. VueScan is easy to use, and has... Read more
AirPort Utility 6.3.6 - Set up and manag...
Note: Most recent release available only within OS X 10.11 El Capitan update. Use AirPort Utility to set up and manage your Wi-Fi network and AirPort base stations, including AirPort Express, AirPort... Read more
Quicksilver 1.3.1 - Application launcher...
Quicksilver is a light, fast and free Mac application that gives you the power to control your Mac with keystrokes alone. Quicksilver allows you to find what you need quickly and easily, then act... Read more

Super Sharp (Games)
Super Sharp 1.1 Device: iOS Universal Category: Games Price: $1.99, Version: 1.1 (iTunes) Description: Your finger has never been so sharp! Cut with skill to complete the 120 ingenious physics levels of Super Sharp and become a cut... | Read more »
Assembly - Graphic design for everyone...
Assembly - Graphic design for everyone 1.0 Device: iOS Universal Category: Photography Price: $2.99, Version: 1.0 (iTunes) Description: Assembly is the easiest most powerful design tool on the App Store. Create anything you can... | Read more »
YAMGUN (Games)
YAMGUN 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: The invasion has begun! Protect the walls of the citadel against waves of enemies! But watch out, you will soon run out of ammo...... | Read more »
Royal Bounty HD (Games)
Royal Bounty HD 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: New World Computing Approved "Hi Guys! looks good so far! keep up the good work. I worked on HoMM 3 and 4 creating all of the... | Read more »
Swords & Crossbones: An Epic Pirate...
Swords & Crossbones: An Epic Pirate Story 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: | Read more »
Camel Up (Games)
Camel Up 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: | Read more »
The Martian: Bring Him Home (Games)
The Martian: Bring Him Home 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Based on the best selling novel and critically acclaimed film, THE MARTIAN tells the story of Astronaut Mark... | Read more »
This Week at 148Apps: September 21-30, 2...
Leap Into Fall With 148Apps How do you know what apps are worth your time and money? Just look to the review team at 148Apps. We sort through the chaos and find the apps you're looking for. The ones we love become Editor’s Choice, standing out above... | Read more »
Tweetbot 4 for Twitter (Social Networki...
Tweetbot 4 for Twitter 4.0 Device: iOS Universal Category: Social Networking Price: $4.99, Version: 4.0 (iTunes) Description: *** 50% off for a limited time. *** | Read more »
Mori (Games)
Mori 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Stop, rewind and unwind with Mori. Time is always running, take a moment to take control. Mori is an action puzzle game about infinitely... | Read more »

Price Scanner via

Save up to $350 with Apple refurbished iMacs
Apple has Certified Refurbished iMacs available for up to $350 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free: - 27″ 3.5GHz 5K iMac – $1949 $350 off MSRP - 27... Read more
Mac Pros on sale for up to $300 off MSRP
B&H Photo has Mac Pros on sale for up to $300 off MSRP. Shipping is free, and B&H charges sales tax in NY only: - 3.7GHz 4-core Mac Pro: $2818.99, $181 off MSRP - 3.5GHz 6-core Mac Pro: $3699... Read more
5K iMacs on sale for up to $150 off MSRP, fre...
B&H Photo has the 27″ 3.3GHz 5K iMac on sale for $1899.99 including free shipping plus NY tax only. Their price is $100 off MSRP. They have the 27″ 3.5GHz 5K iMac on sale for $2149, $150 off MSRP... Read more
Twelve South Redesigns BookArc For Today’s Sm...
Twelve South has announced a redesigned version of their very first product, BookArc for MacBook. Tailored specifically for the newest generation of MacBooks, BookArc holds the new, smaller Apple... Read more
Phone 6s Tips & Tricks – Tips Book For iP...
Poole, United Kingdom based Tap Guides Ltd. has announced the release and immediate availability of iPhone 6s Tips & Tricks, an in-depth eBook available in the iBookstore that’s priced just $2.99... Read more
13-inch 2.5GHz MacBook Pro on sale for $994,...
Best Buy has the 13″ 2.5GHz MacBook Pro available for $994.99 on their online store. Choose free shipping or free instant local store pickup (if available). Their price is $105 off MSRP. Price valid... Read more
Is The iPad Pro Really A Serious Laptop Repla...
Probably not, at least for productive professionals and other power users. Steve Jobs declared that we’d entered the “post-PC Era” with the advent of the original iPad in 2010, a phrase we don’t hear... Read more
Wednesday Deal: 13-inch Retina MacBook Pros f...
Adorama has 13″ Retina MacBook Pros on sale for up to $130 off MSRP. Shipping is free, and Adorama charges sales tax for NY & NJ residents only: - 13″ 2.7GHz/128GB Retina MacBook Pro: $1199.99 $... Read more
uBar 3.0 for Mac OS X – Custom Dock Replaceme...
Brawer Software has announced the release of uBar 3.0, an important update to their popular app and window manager for Mac OS X. uBar allows users to position it whichever side of the screen they... Read more
13-inch 2.5GHz MacBook Pro (refurbished) avai...
Apple has Certified Refurbished 13″ 2.5GHz MacBook Pros available for $829, or $270 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free: - 13″ 2.5GHz MacBook Pros... Read more

Jobs Board

*Apple* Retail - Multiple Customer Support P...
Job Description:Customer SupportSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the Read more
Software Engineer, *Apple* Watch - Apple (U...
…the team that is revolutionizing the watch! As a software engineer on the Apple Watch team, you will be responsible for building world-class applications and frameworks Read more
*Apple* Online Store UAT Lead - Apple (Unite...
**Job Summary** The Apple Online Store is a fast paced and ever evolving business environment. The User Acceptance Testing (UAT) lead in this organization is able to Read more
Hardware Systems Integration Engineer - *App...
**Job Summary** We are seeking an enthusiastic electrical engineer for the Apple Watch team. This is a design engineering position that entails working with Read more
Touch Validation Design (EE) - *Apple* Watc...
**Job Summary** Help launch next-generation Touch Technologies in Apple products. The Touch Technology team develops cutting-edge Touch solutions and technologies that Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.