Read about 5 threads on Mac Pro buzz sound . . . Help!

Discussion in 'Mac Pro' started by Luba, Sep 14, 2009.

  1. Luba macrumors 65816


    Apr 22, 2009
    Hi all, I am getting random (at least it seems random to me) buzz sounds coming from my 2009 2.66 Mac Pro that only lasts for a second. Some suggestions from the other threads recommend that I touch the case when it buzzes but by the time I reach for my MP the buzz stops. I've tighten all the screws in my sleds and pushed them so they are snug in the bay.

    Some have thought the buzz comes from the latch but my buzz sounds like it's from the front of the MP. A Mac Genius told me circuit boards can make a buzz sound from electricity going through it??

    Others have said the buzz comes from the PSU (power supply unit). Where is the PSU in the MP?

    I haven't shaken my MP, which is one of the suggestions I read.

    I think it might be coming from the Super Drive. I took out the Super Drive for about a week and don't recall hearing any buzz sound.

    rgetter recommended re-aligning the ribbon cable (see quote of his post below), but how do you do this? I didn't see a ribbon cable when I took out the Super Drive.

    Any other reasons why my MP is randomly buzzing for a second? Otherwise all I hear is the peaceful hum of the fans.
  2. DougieBaby99 macrumors newbie

    May 11, 2009
    I had the exact same buzzing noise. It's always been random. I think the noise is generated by an aluminum bracket that's behind the optical sled. The bracket is secured by two screws on the top, and has two tabs that slide into notches in the bottom. I believe the panel's tabs are vibrating in the slots, causing a kind of Sympathetic resonance. My solution was to use a simple glue gun and place small dabs of hot glue where the tabs insert into the slots, and coving the two screws on the top (just a dab will do ya). This will dampen the resonance between the bracket and the case. So far I've had the MP running about 15 minutes and NO noise yet. I'll post a follow up later today with more results..

    -Dougie B

  3. Abidubi macrumors 6502

    Feb 13, 2009
    I used to have a buzzing sound when the superdrive spun at high speed (very very loud). Just touching the sled would stop the vibration. So I just jiggled it around a bit and haven't had the problem since. Just seems like if the sled is in the precisely wrong position it will vibrate against the rest of the case.
  4. Luba thread starter macrumors 65816


    Apr 22, 2009
    Thanks for the pics. :) At least I know the problem isn't anything serious. I am not that handy so probably won't put use the glue solution. I am afraid I get it all over the place.

    So if the optical sled was made ever slightly larger and thus more tightly installed, no buzz? Of course if Apple did that it would be more difficult to slide the sled in and out.

    In another thread a poster talked about a ribbon cable not lined up correctly causing the buzz, but his MP was a 2008. Perhaps our 2009 MPs don't have a ribbon cable. Can't find it if has it.
  5. DougieBaby99 macrumors newbie

    May 11, 2009
    ribbon cable

    The ribbon cable is there, well maybe not a ribbon per-se


    This is the Sata cable that attaches to the optical drive(s).

    Someone thought this cable was rubbing against the fan, but in the 2009 Mac Pro there is a fan guard that would prevent the fan making contact with the sata cable.

    If you don't want to use hot glue, perhaps try some kind my moulding putty, as long as it can withstand heat. Anything will work that fills the gap between two metal surfaces and dampens vibrations.


  6. drifter7508 macrumors newbie

    Oct 8, 2008
    My new Mac Pro sound like this. Buzzing irritating sound from time to time.
    Gonna try and see if the glue thing works.

    Turn up the volume! Bad lighting but in the first sequense i got the
    camera behind my Mac pro, then in the front of it.
  7. Whiteyez macrumors regular

    Mar 17, 2009
    The buzz sound (for me) was coming from the front fan that was barely touching the HDD on bay 1. I just put my hard drive on bay 2 and the sound is gone. :D
  8. Luba thread starter macrumors 65816


    Apr 22, 2009
    Mine doesn't sound like that. Yours is more constant while mine is a random burst of buzz then goes away. And I don't have the clicking sound you have. If you can reproduce it I would bring it in.

  9. billtech66 macrumors newbie

    Apr 19, 2009
    Mac Pro, 2009 version also buzzing

    thank you very much for this thread! :)

    My buzz was every 10 seconds, fading in and out during that time period, but starting to drive me nuts. (more so than I usually am :) )

    So, my fix was trying touching the case. and this actually worked if I pressed hard on both sides about half way up towards the front.
    This would get rid of 95% of the noise.

    since I didn't want to have to constantly hold it hehe. I tried another way:

    I raised the front of the computer about one inch, and let it drop. I did this twice, and the noise stopped completely.

    That fixed it. and it is still fixed 3 hours later.

    Yes, the computer was running. but I'd suggest doing this when it is off.
  10. nigel1210 macrumors member

    Mar 24, 2009
    Exactly the same here, moved it around a bit and it stopped.
  11. sparkie1984 macrumors 68020

    Dec 20, 2009
    a small village near London
    how weird!!!!!

    i have this too, is driving me insane! when i move it, it stops....
  12. kellen macrumors 68020


    Aug 11, 2006
    Seattle, WA
    Wow, thats awesome!
  13. billtech66 macrumors newbie

    Apr 19, 2009
    Buzz is still fixed

    RE: buzz, fixed by lifting one inch and dropping the front of computer:

    STILL FIXED at over 4 months later.

    hasn't buzzed since.

  14. Roman23 macrumors 6502

    Jun 12, 2010
    is this a common problem?

    with 2009 mac pros? What do you mean fixed by lifting one inch and dropping the front of the computer? Did you raise it or something?

  15. degl macrumors member


    Jun 12, 2010
    In my 09 MP the buzz come from the hard drives bays supports make a little paper stick and putting over the bays and the sound goes off..

    I tested ejecting the disk from the MacOs and the sound disappear.

    Hope this helps

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