The Robservatory

Robservations on everything…


How hot is too hot?

If anyone out there is using a MacBook (or a MacBook Pro, for that matter), and has access to a temperature probe, I'd be interested in knowing the temperature of your power adapter brick. (Just stick the probe between the adapter and work surface, or hold it on top with a book or somesuch.) Apple just sent me a replacement for my first one, as it was making a scary sounding noise (sort of a grating static-like sound), and was getting to be *very* warm--at least, what I consider to be very warm.

Within an hour or so of powering up the machine, the adapter brick will go over 123F, which strikes me as too hot to be normal. It's basically too hot to hold comfortably for any length of time, and the brick will warp plastic if I set it on such for a period of time. My PowerBook, for instance, never got anywhere near 123F; its adapter stayed cool to the touch. And since both bricks exhibit the same behavior (noise and very high temps), then I think I must have an issue with my MacBook, not the adapter (or perhaps the wall-to-brick cable, but that seems unlikely).

On the other hand, if everyone out there is also recording 123F and can hear the grating static-like noise, then I guess everything's normal...scary, but normal. Still, I find it hard to believe that the brick should be getting that warm, just from the machine being powered up. (As soon as I put it to sleep, the noise in the brick vanishes, and temps return to normal).

June 24 update: I spoke with Apple again this morning, telling them that the new adapter exhibited the same issues as the old. They have agreed (without any prodding on my part) to take my MacBook in for a look-see. So I spent some time this morning reinstalling OS X and removing my third-party RAM chips; it's now ready to go back to Apple on Monday morning.

July 12 update: My MacBook has been with Apple since June 28th, with a status of "Parts on order." Not much of an update, really, other than knowing that I still don't have resolution on the issue.



  1. My MacBook (2.0Ghz White) is exhibiting the same symptoms. It's scalding hot to the touch and crackles constantly. I'm actually a bit wary now of using the MacBook in long bursts. My brick for my old Powerbook (1Ghz) would become warm but never hugely so.

    I'm more concerned about the crackling static noise as nothing that noisy can be healthy for electronics

  2. Kirk: It should be, as it's plugged in to a grounded outlet (I tried many outlets in our home), using the stock cable.

    Cian: I agree the noise is not something one should hear from an electronic device.


  3. The power brick on my PowerBook G4 gets quite warm as well, although I don't have access to a temperature probe.

  4. Sounds like another design flaw by Apple.
    Mine did that sound and I too got it replaced. Haven't had the same luck with my discoloring macbook :(

  5. #5: I wouldn't consider it a design flaw, since I've only found about three others (out of 30 or so who I've heard from now) that have this issue. A flaw in the design would, by definition, affect all the machines.

    I think mine (and the other two) have a flaw in assembly, not design. I've updated the story with the latest from Apple...


  6. Mine certainly isn't making any crackling noises, which as other posters have said is a generally Bad Thing with electronics.

    Temperature-wise, I would only classify it as "warm". It's certainly been hotter in the past, which may have something to do with the fact that my MacBook is running at 98% charge, rather than trying to charge up from a lower level.

  7. I've only ever had a chance to charge my laptop once. But that was when the power adapter got REALLY warm, and made a noticeable static noise similar to a whine noise. The macbook was making a similar noise when it was charging.

    Since then, I've only noticed the same whining noise from the power adapter if I put my ear next to it. And there is much less heat coming from it.

  8. Rob, my MacBook's brick gets VERY warm (although nothing audible, whining or otherwise) when plugged into an outlet:
    1) in my living room or
    2) on the commuter train

    but only slightly warm when plugged into
    3) any other outlet in my home or office, or
    4) any outlet using the long cord attachment instead of the two-pronger.

    While I'm no electrician, my guess is that it's the strength and/or consistency of the electric current of the offending outlets... that's somehow tempered by the long cord attachment.

    Maybe your local Radio Shack geek can help you find a high-end surge protector that can help?

    As for me, whether it's a design flaw or no, I'm simply working around the issue for now (but damn if I didn't make sure I bought Applecare) and making regular backups.

  9. The thing is, I've been using the long cord. And I tested pretty much every outlet in our home, at least those I could reach without moving furniture.

    And if it were just warm, or even really warm, I'd probably be OK with it (though warm enough to warm a piece of plastic seems excessive). But the noise. The noise is not good. Hard to describe, but when you hear it, your first reaction is "oh, that's not a good sound at all!"

    BTW, I plotted a graph of my power brick's temperature over time:

    That's a climb from 80 to 123 and counting in a little over an hour--with the computer doing not much more than being on and displaying a web page or two. Zow.


  10. Have you also tried using another Macbook's power brick, and/or another "long cord" with your own brick? (The long cord and two-pronger both seem to be flawlessly interchangeable with my MacBook's magsafe brick.) This could narrow the possibilities as to which is the offending piece of hardware.

  11. Whoops! I meant to say that **my old iBook's** long cord and two-pronger both seem to be flawlessly interchangeable with those from my MacBook’s magsafe brick.

  12. I have a MacBook with a noisy and hot power supply. Apple is sending a new one, however I plugged in a coworker's power supply and am getting the same. His MacBook is not causing the noise in the power supply. I think it might be some sort of firmware issue. I noticed that noise synchronized with actions taken on the computer. I am not electronics expert, but i am assuming it could either be a firmware issue (I had a G4 that spat out USB noise thru the audio ports), or perhaps there are slight increases in power demand when i am doing an action on the computer, such as scrolling a web page. I just hope it doesnt catch fire...

  13. Hi, I've got the same problem, 220V AC adapter noisy at least while charging, if I keep pressed the mouse button the noise stops totally, the ac adapter gets very hot, but the really strange thing is that the same whine from the ac adapter comes "echoed" but more quietly from the macbook. The cord attached makes no difference.

  14. I use the temp. monitor and mine macbook is around 150F when using with out power supply plug in, when temp do you guy get

  15. Rob,

    Just bought a new MacBook (white-1G RAM, 80 G HD) and before I bought, I asked the salesman about this overheating and "mooing" business. He told me that Apple discovered that in many cases, the MacBooks were shipped with a piece of clear plastic tape over the cooling vent where the lid flips up. The fix was simply to remove the tape! I've used mine almost continuously since I bought it (there was no tape on the vent) and have had no overheating effects or problems. Hope this helps others.

  16. Rob: I experienced the same problem with my power supply upon the third full recharge of my battery. Fear best describes my reaction to the hissing, crackling and whine coming from the brick. It heated quickly, though once the battery charged to full things seemed normal.

    Shortly after that incident, this "screen of" something showed up:[email protected]/184139297/

    Uninstalling a few USB mouse drivers and APE appeared to correct the problem. We'll see what happens the next time I need to recharge. Although, I'm sure a call to AppleCare wouldn't hurt.

  17. Any resolution to the issue? I have the same problem, a macbook with a new power brick that still buzzes and gets very hot when charging the battery and under use. I was told by applecare the I should get the inverter checked. however, when my topcase was replaced, it appears that they did not investigate the issue.

  18. I added an update to the story; thanks for the reminder. Basically, it's still in Austin waiting on parts.


  19. I just switched over to a mac, and pretty much already regretting it. the computer is so effing hot that i need to wear jeans just to keep it on my lap. the genius people wont do anything, and its thirty bucks a call to talk to someone on the phone. when i was with sony, they trouble shooted problems for free over the phone.

  20. After converting from PC to MacBookPro I am having severe regrets. When charging with 2 prong adaptor, the brick as well as the left hand side of the machine is just too hot to touch
    After reading comments, I tried the long cord, giving some marginal improvement. However, the machine and brick runs just too hot
    Living in Thailand, there is a slight language problem with local Apple store, thankfully within 10 minutes walking distance, so I plan to return the machine later this week regardless
    I will keep you informed of my progress

  21. I own a HP Pavilon computer and my adapter gets really hot as well, almost to the point where I can't touch it, so this isn't just for Macs, but it hasn't caused me any trouble.

  22. I too have had issues with the brick hissing/crackling as well as getting super hot. Like Court said, I have noticed that it also corresponds at times to what I'm doing on the computer, such as even just clicking on the mouse.

    Oddly, I have just never thought about the fact this might be dangerous. I guess I should take it in....


  23. My iBook's power brick is also very hot. I thought it had gone wrong or something but I guess it gets really hot when doing a long charge. I usually keep it plugged and charged but I had gone using it wirelessly andused up most of the battery (6% left). I was charging it and when it reaced 65%, I felt it and it was so hot that I could could not hold it for more than 5-10 seconds. I then unplugged it worried it was too hot. I am currently letting it cool and then I will resume charging.

  24. i have a hp that the cord got so hot it melted the tip inside the computer it is a little over a year old

  25. Hi, I stumled across this while looking for a solution to my problem, which is the same, except that I have a dell inspiron. Looks like this isn't only happening on macs, as some people seem to be saying. My adapter gets extremely hot, and sometimes (i guess when it overheats, I don't know) the light goes out and the computer will be running on battery power! When I let the brick cool down a little, and then plug it back in, everything works fine again. I too got my adapter changed, but had to pay for mine (I didn't bother asking for a free replacement, because this started happening after the warranty was up.) Obviously, it didn't help at all. This really isn't normal, but what can I do? This is a standard ac adapter, and its really frustrating, because I wonder if this is a fire hazard.

  26. Have had my MBP 17" for about 7 months and never had a problem until today when the computer is doing CPU intensive encoding. The brick got too hot to even touch.

    I unplugged it from a short 6' extension cord it was plugged into and let it cool, then plugged it directly into the wall. This seems to have solved the problem.

    It would appear to be the brick was having trouble pulling in enough AC current to power the computer requirements under heavy load.

  27. As I recall from two years ago, they sent the machine back, and it worked much better. However, I got sick of the glossy screen, and swapped it for a MBP in November of 2006.


  28. My "block" is BOILING to touch!! I got scared today, (which is why I searched this forum), because I was watching a movie on my laptop, fell asleep, and woke up with a BURNING sensation on my bed! The "block" had fallen on to the carpet, so it took me a while to realise it was that which had caused the heat, but when I went to pick it up it practically scolded my hand! Nothiong was on fire, but I could smell a slight burning coming from the adapter/block...

    I don't think apple will replace it, (i've had it for a couple of years), and I don't know if it's worth spending money to get it changed....

    IS this too hot? Could or start a fire? Am I slowly killing my macbook by putting too much stuff on it? (think: motion, colour, final cut...)


Comments are closed.

The Robservatory © 2022 • Privacy Policy Built from the Frontier theme