7 Replies Latest reply: Apr 4, 2010 12:46 AM by Helios1979
Helios1979 Level 1 Level 1 (0 points)
Hello,

i have a macbook unibody (white) and since i updated to 10.6.3 i hear a quite humming noise under the F1 and F2 buttons. The noise is like bzzz pause bzzz pause bzzz.... and when i use the trackpad than its like a constant bzzzzzzzz. I used the Apple Hardware Test and everything is ok. I noticed that in the Hardware Test Menue the humming noise isn´t there. It starts when 10.6.3 is already booted.

Have someone the same problem?

Thanks

macbook unibody white, Mac OS X (10.6.3), 4Gb RAM
  • lepkitty Level 1 Level 1 (105 points)
    i'd try an smc and pram reset and see if that helps. also try safe mode to see if it buzzes there as well.
  • Helios1979 Level 1 Level 1 (0 points)
    Thank you very much for your comment lapkitty. The things with the reset don´t worked for me. But your idea with the safe mode was interesting because in safe mode i hear no humming noise. But in normal state its there. Hmmm oh man
  • lepkitty Level 1 Level 1 (105 points)
    interesting...try repairing permissions in disk utility then restart
  • Allan Eckert Level 8 Level 8 (47,455 points)
    Hi Helios1979;

    If in safe mode you don't hear but you do in normal node, that indicates it is something that you have in your startup list because everything in the startup list is ignore during a safe startup. Check what is in your startup list for the culprit.

    Allan
    tiger
  • Helios1979 Level 1 Level 1 (0 points)
    Thank you Allan Eckert,

    but the only thing in my startup was iTunesHelper. I disabled it but nothing changes. Hmmm is this perhaps a hardware issue that appears in special situations like normal mode?

    P.s.: It is a very quite hum noise but it is notable in silent rooms and it is irritating.
  • Allan Eckert Level 8 Level 8 (47,455 points)
    Hi Helios1979;

    Thank you for the helpful star.

    I am sorry that the startup items didn't work out for you. One of the other differences to a safe boot is that only the required kernel extensions are loaded. Do you have any third party hardware on your Mac that might being load a kernel extension in normal mode?

    The only other suggestion I can think of is to try watching Disk Activity in Activity Monitor and see if that shows any relationship to the noise.

    Allan
    tiger

    Message was edited by: Allan Eckert
  • Helios1979 Level 1 Level 1 (0 points)
    After searching the web i am now sure what the problem is. 2006 till 2008 there was a similar humming noise in many Apple notebooks. The problem called whining was because of the C4 sleep state of the cpu. In Idle the cpu deactivate one core when there was nothing to do. This happens many many times in a second an because of this there was this noise. I read that Apple offered to those people a new logic board to decrease this noise.

    I thougt the humming was coming from the F1 and F2 buttons now i am sure it coms from the W,A,S and D buttons.

    I hope Apple offers today the same option.