Apple Notebook Power Adapters: Dangerous By Design?

Written by: Adam Christianson

Categories: Editorial

Apple Power AdapterIn these days of countless stories of exploding Dell notebooks and massive Dell power adapter recalls, Apple has seemed relatively immune to these sorts of problems. Every once in a while, some odd thing came along, but it seemed like relatively calm waters. I fear, however, the sense of safety for Mac notebook users may be coming to an end. There have aready been hints of problems with the white brick adapters and scattered reports of various failures. Who can forget about the class action settlement around the previous Apple adapters?

Recently, I have had problems with my Apple PowerBook power adapter which has lead to me take a close look at their design and safety. With no apparent trigger, no visible damage or other warning of any kind, my adapter began to spew sparks and flames and burn the paper notepad on which it was sitting. Thankfully, I was literally sitting right in front of the adapter when it happened and I was able to instantly unplug it – but not before it damaged the paper notepad and my PowerBook. And it could have been much worse.

I was surprised that an adapter could possibly do something like this – it had to be a fluke, I thought. So I posted a page that showed photos and gave some details of my problem. This quickly attracted many thousands of visitors, some of whom contacted me to share similar stories with me. Fortunately none of them were injured, but reports ranged from simply needing a new adapter to their notebook being rendered a nearly useless five and half pound hunk of aluminum and plastic.

The fact this wasn’t entirely isolated piqued my curiosity. Talking to a few people associated with some Apple Authorized Resellers & Service Providers found they had seen this failure many times before. So what was causing it? Why did these adapters so easily short out and smolder or even catch fire? Could it be prevented? Has Apple made improvements in this department? Will it happen to me again or other users?

How It Starts

The adapter provides 24.5 volts of direct current electricity – enough to generate a bit of a spark when it arcs. In the case of the adapters that burn and spark near the DC out, the internal cable insulation wears down to the point that there is little insulation between the wires left. At some point, there’s just so little left, the cable is able to spark – potentially with no visible external triggers or warnings – and this spark is enough to cause the plastic to smolder and/or burn.

Obviously, the plastic used in the insulation is at least slightly combustible, as evidenced by my experience. Furthermore, it appears that it may be designed in such a way that the internal cable insulation is less durable than the visible external insulation. The result is that the cable appears to be perfect – at least on the outside – yet on the inside, it could be precariously worn. There’s no way a consumer could reasonably be expected know this or anticipate such a failure.

It seems Apple has been aware of problems in this area of the adapter. Early versions of the white brick adapters (such as the one on the snow iBook G3 I purchased years ago) used an inverted cone type design to reduce stress on the cable. However, it seems that wasn’t satisfactory, so Apple re-designed that area to be flat and placed a short rubber sheath that extends along the cable as it leaves the adapter. Unfortunately, it seems evident even that isn’t sufficient to mitigate the stresses that occur even in normal, careful use. Like many Mac users, I don’t roll my adapter cable around the small feet and have been very careful with my adapter, yet it still managed to short, spark and burn.

Don’t forget that Apple’s previous adapter designed have resulted in various recalls and even a class action settlement.

A Preventable Problem

Of course, combustible materials, poorly designed wire stress management and fragile insulation isn’t alone enough to start a fire. What makes this so dangerous is the fact that the Apple power adapters do not integrate sufficient short circuit protection on the DC side. This means, when the wires touch or nearly touch, they will arc and generate a spark – not once, but again and again, as long as the adapter remains plugged into electricity. And because it happens on the DC side, it does not trigger any circuit breakers, household fuses or GFCI outlets.

This is a huge problem – even my $35 PC ATX power supply will barely emit a single tiny spark before the entire thing powers itself off and requires me to disconnect and reconnect the power before it delivers any more current to the DC side. The Apple notebook adapters are a lot more expensive and – hopefully – better designed than the local computer store’s $35 special on a generic Chinese ATX power supply. Yet… why doesn’t the Apple power adapter turn off when it detects a short?

Still No Improvements

Now… everybody obviously asks, "Well, surely Apple has improved their adapters?" People have even written to inform me that Apple now uses "sturdier" cables on their newer adapters, so this problem shouldn’t happen anymore. However, unless they’re talking about a different adapter – maybe one of the new MagSafe adapters, which obviously don’t work with the PowerBook – they’re wrong.

I spent time closely inspecting the original adapter that came with my PowerBook and caused the problem, comparing it to the model Apple sent me as a replacement and another Apple branded power adapter I purchased new from a local computer store. They were all identical. The reinforcing rubber "bootie" was the same. The cable appeared to be the exact same gauge. They even all exhibited the same lack of proper short protection and proved able to arc endlessly without tripping any breakers, fuses or GFCI outlets.

Apple, I love the innovative and alluring design of your computers. I love how Mac OS X integrates the power of Unix with the strength of commercial software like Photoshop all wrapped into a stable, intuitive operating system. But, why can’t you design a safe, reliable power adapter, or at least fix your mistakes?

There are 10 comments on Apple Notebook Power Adapters: Dangerous By Design?:

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  1. Phillip | Aug 12 2006 - 02:33

    My Powerbook is 2 to 3 years old and my power supply and the one for my wife’s ibook stopped working withing weeks of each other.
    Being the sort of person I am, I took them appart to see what was wrong.
    I discovered that the rubber of the power cable itself had split inside and it was shorting out against itself just at the point that it leaves the actual power supply (I had noticed that the cable itself was getting very hot with use). This is clearly very dangerouse and could easily have lead to a similar (or worse) fire!
    Anyway, I cut the cable back and soldered it in and it has worked perfectly ever since (excpet of the fact it is held together with white insulating tape!)
    There clearly is a problem with these power supplies failing and they are bl@@dy expensive to replace but I’m not sure what Apple can do?

  2. Galen Zink | Aug 12 2006 - 04:50

    It appears the link to the full article got excluded from this post. Until Adam can fix it, here’s the full article:

  3. Missy | Aug 12 2006 - 04:52

    My original iBook power supply cord frayed and then separated right where the plug is terminated on the iBook side. I had to buy a new one. The cable did not seem very sturdy unless you let your cable sit and never do things like pack your laptop in a backpack and take it places.

    For the Powerbook – I have noticed the plug at the laptop blinks and seems to have a bad connection, and it is warm but not hot to the touch. The brick also gets very hot when it’s left on a cloth surface.

    I know the power supplies are designed for elegance as much as you can do with that kind of thing, but in the case of power and batteries I think safer is more important that prettier.

  4. shane | Aug 12 2006 - 10:03

    no problems here for 2-3 years except i ripped the cable apart by tripping over it while plugged in I have not heard of any issues and it is a fairly bold headline that there is a design fault.. another terrorist ?
    we dont need any more terror struck into our hearts unneceesarily

  5. Stu Hamstra | Aug 13 2006 - 06:43

    Actually had this problem with the power supply for my iBook about 3 years ago – while on an AMTRAK train to Boston. Even though it was plugged in, the battery wouldn’t charge and I didn’t see the frayed connecion (and a tiny spark when I wiggled it) until almost to Boston. Had to buy a new unit – 30 bucks – for just the small frayed connection. Fortunately I was on my way to a MAC expo so new unit was readily available (this was before APPLE STORES). Easy fix would be to make it possible to diconnect the wire from the unit just like the other end disconnects from the iBook.

  6. Mike Talmadge | Aug 13 2006 - 07:24

    From a design perspective, Apple (or any manufacture) has a tough obstacle to achieve with any electrical cord that is used in a day to day routine such as the Apple power supply. Any wire that is wrapped and unwrapped on a regular basis is subjected to failure, that is the nature of wire. The best method to prevent wire fatigue failures would be to not wrap and unwrap wire or at least keep it to a minimum, of course this might not be practical for everyone. I linked some pictures of some do’s and dont’s to help prevent these failures prematurely. This should help to extend the length of your power supply or any wires for that matter.

  7. Ryan Ellerbe | Aug 14 2006 - 01:35

    Well I never really noticed my macbook brick was getting really hot until last night. I have been just using the travel part to plug into the wall here at my house. They macbook had went to sleep due to the battery needing to be recharged. I went and plugged it in, and a hour later I came in the room and heard a buzzing noise. I realized it was the brick that was making the noise. When I touch it, it was really hot. Now I don’t think it was to hot to start a fire, but it scared me. Well I decided to unplug it over night just to be safe. I now use the extention that comes with it and it seem to not get as hot. So please be careful when charging your macbook. You could wake up to a fire.

  8. anonymous | Aug 15 2006 - 04:37

    I agree with the other poster, be very careful where the cable bends. In fact I don’t even wrap my cable around the brick. Giving the cable slack and making sure when it is in use it has slack is very important. If the bend feels at all unnatural, stop. In addition, when you plug in the adapter, look directly at it as you push it in the port of the computer. The connector can be subject to bending and sometimes if misaligned can fall in if forced too hard. When you pull it out, pull it by the bulb. My adapters have lasted years without any issue. The lesson of the day here is slack. And perhaps when you consult with AppleCare about your brick let them know it should be clear in their instructions how much slack is needed to prevent failure.

  9. Mark | Aug 16 2006 - 01:31

    I’ve had this problem on two different bricks. The first was taken back to the Apple Store, where I was turned down by the “Genius”, because he considered this to be “normal wear and tear”. The manager was only slightly more helpful, actually replacing it after much polite persistence on my part, but he was pretty rude. He stopped just short of calling me a liar regarding how the damage occurred. (That was at the Grove Apple Store.)

    The other was replaced when I had to send in my Powerbook for a repair. I included a note with the laptop, asking the repair tech to take a look at the power adapter, told him he should have lunch on me, and taped a $10 bill to the note. When the Powerbook came back, there was a brand new brick!

    I don’t think I should have had to have paid for a new one, but after my experience with the Apple Store, $10 was cheaper than the $30 I’d have to pay for a 3rd party replacement. It was also a calculated risk. Maybe the tech wouldn’t have access to the adapters, or maybe he’d just have lunch without any quid pro quo.

    Anyway, big thanks to the tech, where ever he or she is. You restored a little bit of faith in me, and I hope you enjoyed your lunch.

    More recently, I purchased a 12″ Powerbook, and the strain relief on the wire as it enters the AC adapter brick was beefier. So far I have had no problems.

  10. Dan | Aug 23 2006 - 01:06

    I have a powerbook that’s two and a half years old and in class I smelt something burning and checked to see what it was. I saw that my power adapter had fried at the same spot as yours. It scared me because it could of set off a fire in the class room and more importantly I was concerned about getting electricuted. I’ve been concerned for a couple of years now about how hot these things run. Recently, a home in Vancouver Canada, at a fellow classmate’s apartment building, caught fire because of a laptop that caught fire. I know that design of the powerbook uses the case to disperse heat and cool the laptop down but I question if it really is that good of an idea.