11 Replies Latest reply: Jan 31, 2015 3:03 AM by Zeitgeber
jmbrysk Level 1 (0 points)

So my MBP, just an hour or so ago, failed to shut down.  I click Apple->Shut down, but the computer instead restarts and while loading OS X, gives me an error that says "You restarted your computer because of an error."  The fans are maxed out right now, there is -no- process causing thisl  Also, I use iStatMenus to monitor my temperatures, and all of the CPU sensors have gone offline, iStat is only reporting temps for the hard drive and battery.


iStat also seems to have lost the ability to control my fan speeds.  Uninstalling and reinstalling iStat did nothing.  Resetting PRAM and the SMC have done nothing either.  Any ideas? 

MacBook Pro, OS X Mountain Lion (10.8.2), 2.4 Core 2 Duo, 8 GB Ram
  • John Galt Level 8 (45,968 points)

    Run Apple Hardware Test:




    You must remove the firmware password, if one has been set, before you can use AHT.

  • jmbrysk Level 1 (0 points)

    Holding "D" at bootup just seemed to launch the OS X recovery application on Mountain Lion.  Was there some sort of UI for the Hardware Test that I was supposed to see?

  • John Galt Level 8 (45,968 points)

    To start up your computer in Apple Hardware Test:

    1. Press the power button to turn on your computer.
    2. Press and hold the D key before the gray startup screen appears. If Apple Hardware Test does not start up, see the Additional Information section at the end of this article.
    3. ...















    Additional Information

    Apple Hardware Test is included on the DVDs that are shipped with some Macintosh computers. If the copy on your hard drive becomes unavailable, use the DVDs to run Apple Hardware Test.

    • For Intel-based Apple computers that shipped with Mac OS X v10.5.4 or earlier, Apple Hardware Test is located on the Mac OS X Install Disc 1 and should be included with your computer.
    • For Apple computers that shipped with Mac OS X v10.5.5 to 10.6.7, Apple Hardware Test is located on the Applications Install Disc 2 and should be included with your computer.
  • jmbrysk Level 1 (0 points)

    Yes, I read the article, and no, that did not help.  Still can not run the hardware test.

  • John Galt Level 8 (45,968 points)

    What happens when you hold the d key while starting with the DVD - whichever one bears the words "Apple Hardware Test" or "AHT version xxx" printed on it? Press and hold the key as soon as you hear the startup sound.


    It will not load AHT if you set a Firmware Password.

  • jmbrysk Level 1 (0 points)

    With the DVD in, I may have seen, for a split second, the multilanguage "Your computer has encountered an error and needs to shut down" message over the grey boot screen.  But again, it's only for the slightest fraction of time before I get the Apple logo which eventually boots into the install DVD. 

  • John Galt Level 8 (45,968 points)

    Does it occur whether or not you hold the d key?


    The Kernel Panic message you may be seeing could be caused by a corrupt version of AHT on your Install disc. In that event the Mac may revert to a normal boot.


    An inability to run Apple Hardware Test will hinder troubleshooting, but it is more than likely it will report something you already know - that one or more CPU sensors have failed.

  • jmbrysk Level 1 (0 points)

    Seems like it only happens when I hold D while the DVD is in the superdrive.  I don't see the message without the DVD in, regardless of whether I'm holding D or not.

  • John Galt Level 8 (45,968 points)

    Upon restarting your Mac, do you get this dialog box?


    Your computer restarted because of a problem.png


    If you do, click Report, and copy the text in a reply.


    This is likely to be moot anyway, as it appears the CPU temperature sensors have failed. I would not put too much additional effort into getting AHT to run.


    OS X: About kernel panics

  • jmbrysk Level 1 (0 points)

    I get that box every time I start the computer up now.  I will provide the log tomorrow, I'm heading to bed since I work early.  For what it's worth, my Windows 7 boot camp partition has software that monitors temps.  That software is able to successfully read the temps of the CPU and motherboard, so I don't think I have a hardware problem.

  • Zeitgeber Level 1 (0 points)

    Was this ever solved? I have a late 2008 (first gen unibody) and my fans are out of control and neither GPU or CPU are reporting temps.  This happened to me after my computer just shut off twice on its own within an hour. My battery no longer works either.  The green LEDs don't show that its charging.