14 Replies Latest reply: May 6, 2012 7:07 AM by iChasert
iChasert Level 1 Level 1 (0 points)

Hello, I own a MacBook pro 7.1, updated to le latest firmware;

 

About a week ago I noticed it was running at high rpms; I initially thought it was due to bad ventilation or high cpu usage;

 

I reinstalled osx via internet recovery (I had also frequent kernel panics, about one time per month), so it was updated to the latest version. The problem was stille there, so I reset the SMC and the PRAM; still, no luck; I've tryed a Gnu/Linux live cd and the mac showed the same behavior.

 

Cool, isn't it?

 

Sometimes it doesn't happen at all, other times it runs at the highest speed for hours, and sometimes it runs for about 15 minutes at high speeds, then behaves normally.

 

I went to the local Apple store, the genius guy has tried to boot via netboot a utility, but it get stuck at "loading, please wait", so they took my macbook for additional checks.

 

They told me I'd need to change the logic board; now, no doubt it wold have solved the issue, but it was over 500$ (more than a new (pc) laptop with sandy bridge) and I don't see how this could be an hardware problem: the cpu stays cool, so the sensors are working fine and report the correct temperature; I've checked the sink and it seems to be fine, there's only a little dust. It looks like a firmware bug. Here's an iStat screen:

 

Schermata 05-2456052 alle 00.46.14.png

 

any idea? I don't necessarily want it to be fixed, I'm just curious.

 

Thanks in advance and sorry for my english


MacBook Pro, Mac OS X (10.7.3)
  • 1. Re: MacBook running constantly at 6200rpm
    gatorfantom Level 1 Level 1 (0 points)

    I'd be curious to see what your Activity Monitor and Console are showing in the following three states:

     

    A)  when your machine is "behaving normally"

    B)  right after the RPMs have ramped up

    C)  right after the RPMs return to a normal state

     

    Want to post some screenshots of each state? (Before snapping, try to enable as many columns in "View" as possible. And in Activity Monitor just sort everything by the "%CPU" column.)

  • 2. Re: MacBook running constantly at 6200rpm
    eww Level 9 Level 9 (52,975 points)

    Run the extended version of the Apple Hardware Test. I expect it will return an error message containing the string "4SNS," indicating that one of your machine's temperature sensors is faulty. When a temp sensor is bad, the fan or fans (your 13" has one fan, the 15" and 17" MBPs have two) run at top speed as a precaution, just in case the bad sensor is failing to report an overheating condition. There is usually no such condition, but because many of the sensors are soldered onto the logic board or incorporated into other components that are soldered to the board, a board replacement may be the only remedy for the roaring fan.

  • 3. Re: MacBook running constantly at 6200rpm
    iChasert Level 1 Level 1 (0 points)

    so, thanks. I tryed to run the apple hardware test; http://support.apple.com/kb/ht1509

     

    I connected the macbook via an ethernet cable to my switch, then I started it up holding down the D key; The screen remained gray for 30 seconds, then the login screen appeared (I'm using FileVault); I tryed two times: the first, holding D down before pressing the power button, and, the second time, holding it afeter pressing the power button, but before the gray screen appeared...

  • 4. Re: MacBook running constantly at 6200rpm
    MittWaffen Level 1 Level 1 (80 points)

    Take it into apple, you might need fan replacements.

    Or try another SMC/Pram reset just for good measure.

     

     

    Goodluck.

  • 5. Re: MacBook running constantly at 6200rpm
    eww Level 9 Level 9 (52,975 points)

    iChasert: Run the Hardware Test from one of the DVDs that were shipped with your computer. See the "Additional Information" at the bottom of the article you linked to learn which disc it's on, if the disc label doesn't tell you.

  • 6. Re: MacBook running constantly at 6200rpm
    iChasert Level 1 Level 1 (0 points)

    Unfortunately I only have the application install dvd;

     

    For some Apple computers that shipped with OS X Lion, if Apple Hardware Test cannot be found on the hard drive, an Internet-based version starts up instead. An Internet-enabled connection via ethernet or Wi-Fi is required to use this feature

  • 7. Re: MacBook running constantly at 6200rpm
    eww Level 9 Level 9 (52,975 points)

    If AHT isn't on that disc, you'll have to have the MBP tested at an Apple store or authorized service provider. AHT isn't available as a download.

  • 8. Re: MacBook running constantly at 6200rpm
    eww Level 9 Level 9 (52,975 points)

    Your machine didn't come with Lion on it, so that instruction doesn't apply.

  • 9. Re: MacBook running constantly at 6200rpm
    OGELTHORPE Level 7 Level 7 (25,670 points)

    If you have the Applications CD, look in the upper right hand portion of same.  There should be a short paragraph about the Apple Hardware Test.  Or just put the CD in the Optical drive holing down the 'D' key.  That will pull up the hardware test. 

     

    Ciao.

     

    (I also have a 2010 MBP)

  • 10. Re: MacBook running constantly at 6200rpm
    iChasert Level 1 Level 1 (0 points)

    so thanks;

     

    I tought it would have applied anyway because the macbook is updated to the latest firmware and supports netboot/internet recovery. I've found the 10.6 os install dvd, but it didn't have the aht.

     

    As suggested by OGELTHORPE, It's on the Application Install Dvd;

     

    I ran it, and the result is...

     

    No trouble found!

     

    Now I'm performing the extended testing

  • 11. Re: MacBook running constantly at 6200rpm
    eww Level 9 Level 9 (52,975 points)

    Is your fan roaring while the test goes on? If there's an intermittent fan problem, the test may not discover it.

  • 12. Re: MacBook running constantly at 6200rpm
    iChasert Level 1 Level 1 (0 points)

    sure, it is, and the macbook is also quite hot; I think that's normal

  • 13. Re: MacBook running constantly at 6200rpm
    gatorfantom Level 1 Level 1 (0 points)

    Again -- screenshots might help.

     

    I'm not insinuating that you could be overlooking something blatant -- such as a runaway process. It's the not-so-blatant / seemingly innocent stuff that someone else here may recognize from a past experience.

  • 14. Re: MacBook running constantly at 6200rpm
    iChasert Level 1 Level 1 (0 points)

    well, actually Activity Monitor says "% Idle: 92%".

     

    I really don't see how a screenshot could help. anyway, here's ps aux:

     

    http://pastebin.com/raw.php?i=DRHnNvwP