MBP Heat Cause Discovered & Solution!

Discussion in 'MacBook Pro' started by jsbarone, Feb 2, 2008.

  1. jsbarone macrumors regular

    May 8, 2007
    Hey Guys,

    I have a launch 2.4GHZ MBP that I've been mostly happy with, save it's super hot temps. Lately I've been getting actual shutdowns to save the processor, which scares the crap out of me. When I got it I was seeing temps of 80c+, so I took the computer in a few weeks after getting it and Apple supposedly repaired the problem by replacing the logic board.

    Anyways, so up until now I haven't had any apps running that required a lot of processor use, but last week I decided to run Seti@Home via BOINC and discovered that my heat problems are indeed still there, only this time they top out at 105c. I almost lost it because my computer was shutting down due to heat, I was seeing temps of 105c and I figured Apple wouldn't be able to help me, so I picked up some Arctic Silver and applied it to the Chipset, CPU and GPU. I put the computer back together sans the battery and while running BOINC I'm seeing temps maxing out at 50c. "Great!" I think, problem solved...only as soon as I put the battery back in, BAM! 100c right off the bat.

    Battery out, 50c, battery in, 100c. I tried it with my spare battery too and it did the same thing, so I don't know what the deal is. I'm running it without the battery for now to see how it does overnight, but for now that seems to be the solution.

    For you all who have hot MBP's, can you try taking your battery out and see if you get cooler temps too? I'd like to know whether or not I need to ask for a new MBP.


  2. AirmanPika macrumors 6502


    Jun 19, 2007
    Vandenberg AFB, CA
    You might wanna check your CPU Speed. The reason its cooler is because its not using the battery charger AND its downclocked the CPU 1000 MHz (Thanks for that apple...bleh).
  3. azhelkov macrumors member

    May 31, 2005
    With battery out you shut down second core of CPU. Of course it produce twice less heat.
  4. scienide09 macrumors 65816


    May 5, 2007
    With the battery out, there's also a nice 4" by 3" of extra space for air to circulate, and therefore to help the heat dissipate.
  5. kolax macrumors G3

    Mar 20, 2007
    The battery provides power too even if it is being charged and plugged into mains.

    The power adapter cannot provide enough power on its own. It isn't a PSU, it is a charger.
  6. Animalk macrumors 6502

    May 27, 2007
    Montreal Canada
    As far as i know, removing the battery reduces the frequency of your cpu by half and does not shut down one core as was posted above. That would be the reason why you are running much cooler without the battery in place. Your temperatures are exceptionally high and should be looked into seriously.

    Good luck.
  7. Shannighan macrumors 6502a


    Jul 26, 2007
    Buffalo, NY
    i have aquick question. you say that if you take the battery out, you will have less CPU speed. can you do this manually so you use less power, generate less heat, causing the fans be be able to run slower for less noise?

    the reason i ask is because i plan on talking it to school and will problaby be the only kid in class with a laptop and i dont want to disrupt every body else.

  8. Sesshi macrumors G3


    Jun 3, 2006
    One Nation Under Gordon
    Are you using it on a particularly insulating surface? If it's shutting down due to a thermal error there is clearly something not right, even for rubbish Apple hardware.

    As others have said, you probably should get it looked at.
  9. cal6n macrumors 68000


    Jul 25, 2004
    Gloucester, UK
    And what do you think a charger is, if not a power supply?

    @ OP: As for the excessive heat generated by some MBPs, this is very old news. Everyone who has looked into this (apart from Apple and their apologists) has concluded that poor assembly involving excessive quantities of thermal paste is the main cause.

    I posted my take on the issue here.

    Bottom line is that you have 3 choices:

    1. Live with it. (worst solution)
    2. Keep sending it to Apple until they get it right. (best choice for non-techies)
    3. Strip and rebuild the machine taking care to use the thermal paste correctly. (best solution for techies)

    Personally, I chose the 3rd solution and saw a reduction in temperatures of 15 C across the board.
  10. PimpDaddy macrumors 6502


    May 9, 2007
    Surely taking the battery out isn't a fix IMO. The problem is still there. And even though I've heard of hot MPB's, your MBP wins the 1. price ;)

    I've read a thread made by a guy who took his MBP apart. Cleaned it of all the old cooling paste and applied new cooling paste in the right amounts and in the right places. Made his MBP about 10-15c cooler if I'm not mistaken.
  11. Killyp macrumors 68040


    Jun 14, 2006
    My launch MacBook Pro (1.83 GHz) kept on overheating. The case sagged because it got so hot, and it went through several logic board replacements. In the end Apple replaced it (2 months out of warranty) with a brand new 2.2 GHz 'current gen' MacBook Pro...
  12. kolax macrumors G3

    Mar 20, 2007
    I was referring that the charger is not a dedicated PSU, like those found in desktops.

    The charger is there to provide power to the battery in order for it to charge up, not power the whole laptop on its own.
  13. DocSmitty macrumors regular

    Jan 7, 2008
    Lincoln, NE
    Soooo. If you can run the laptop indefinitely when it's connected to AC and the battery is charging, wouldn't that indicate that the AC supplies enough power to run the computer? The laptop's PSU is built into the battery rather than into the computer itself? That's got to be one of the worst designs ever..
  14. Fezzasus macrumors regular

    Jan 24, 2008
    I don't think you're getting this. Say your battery runs down, you plug your computer into the charger and the charger is now powering both the computer and charging the computer = more current drawn than running the computer on its own.

    The battery doesn't do anything but store charge for when the computer isn't plugged in. It doesn't power the computer when it's plugged into the mains. it IS just like a desktop powersupply.
  15. ayeying macrumors 601


    Dec 5, 2007
    Yay Area, CA
    I'd say take it back to apple and have them replace it. Keep replacing it until you think its fixed. Currently, my macbook only maxes out at 70 deg C with both cores at 100% and fans at 5000 rpm (max is 6200 rpm)
  16. kolax macrumors G3

    Mar 20, 2007
    I won't lie and say I know a lot about this - but it has been discussed in detail before and I am trying to type things off the top of my head.

    I'll try look up an old post that explains it, rather than trying to explain it myself since I have the chance of writing utter crap!
  17. azhelkov macrumors member

    May 31, 2005
    My bad, yes removing battery throttle down CPU not shutting down core. And yes you can do it manually using shareware app CoolBook.
  18. iMan G5 macrumors member

    Oct 10, 2007
    Uhh he opened it up. Applied AS5. Pretty sure that is the warranty out the window already.
  19. jsbarone thread starter macrumors regular

    May 8, 2007
    Thanks for all of the replies. I did apply some AS5 but it didn't do any good. I took the MBP down to the Apple Store this morning and they determined that they're going to replace the logic board & heatsink & fans to try and eliminate the problem. I doubt they'll notice my AS5 job...if they do I'll play stupid.

    As a side note, they're replacing it with a 2.6ghz logic board instead of the 2.4 that I paid for. Stupid Genius or does this add some credibility to new MBPs coming out?

    Also, just in case I get some haters about me opening up the MBP...I'm A+ & Net+ certified and worked on PCs, Macs, Notebooks, etc at CompUSA for years...now I work for a hospital doing similar things. I probably did a better job than the Apple Techs will when they open it up---
  20. iMan G5 macrumors member

    Oct 10, 2007
    Had I known this, I wouldn't have said anything most likely. Also that is two people on this forums I know of that are gettting/have gotten 2.6Ghz machines instead of 2.2 or 2.4.
  21. /dev/toaster macrumors 68020


    Feb 23, 2006
    San Francisco, CA
    Interesting ... I had some heat issues with my MBP when I first got it, but it never locked up. However, now I am starting to get serious problems. Its so bad I can't play any games for more then 20 minutes.

    I had tried this in the past but it never affected my temp. For reasons unknown today is different. I went from 195 degrees F down to 150 degrees F on playing WoW. After 2 hours no lockups.

    Thats a huge difference. I wonder what is causing it.
  22. Fry-man22 macrumors 6502


    Nov 25, 2007
    This is incorrect; the power brick is king and everything runs best when that is the power source. On my old Dell M1710 with a 7900GTX 512MB (a real gaming card not a mid-level thing like the 8600M) running on battery clocked down the CPU and GPU but the brick let it run at full clocks (as expected), even running on the brick with no battery. The XPS had a 130w brick and the Macbook Pro is only 85w but the power requirement (TDP?) of the hardware is MUCH lower given that the 7900GTX go requires juice almost like a desktop card. When the power brick is present the only thing the battery does is sit there and charge (hence the reason you can remove it with no ill effect).
  23. Csmitte macrumors 6502


    Oct 11, 2007
    Nah not unless his problems are caused by what ever he did, and since apple already opened it. whose to tell.
  24. himansk macrumors regular

    Oct 16, 2006
    You guys are not getting the point there. The power adapter is rated to provide enough juice to run the laptop, no doubt about that, but it is not guaranteed to provide it continuously. If there is a power spike, decreasing the power suddenly for a millisecond, the battery would switch in and provide the required power to keep the laptop running without damaging the components. If you instead keep it on AC adapter only, the power spike could cause a shut-down as well as even a component damage. Electronics are very sensitive, thats why (almost?) every manufacturer recommends having a battery plugged while working on AC power, even if it is not charging.

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