17" Hi-Res Glossy Penryn MacBook Pro high pitched noise related to display brightness

Discussion in 'MacBook Pro' started by PeterKW, Apr 4, 2008.

  1. PeterKW macrumors newbie

    Apr 4, 2008

    I have a Penryn 17" MacBook Pro (2.5Ghz) with the Hi-Res Glossy LED display, the display is great, no dead pixels or any yellowing, however a high pitched noise is emitted from the lower right corner, approximately where the backspace key is. Depending on the brightness the noise varies, going away when the backlight is disabled. As soon as the backlight is active the noise is there, turning to full brightness won't make it go away. Other users have reported similar problems when using Win XP or Vista in combination with Boot Camp. However, I have this noise when using Mac OS X (no Boot Camp installed so I can't check whether it's there as well). The noise is not really loud, but you can hear it clearly when putting your ear close to the backspace key. In a silent room you can hear it when sitting in front of the MacBook Pro. If you move the slider for the brightness it becomes more apparent as you can hear it change its frequency, especially when moving the slider to the far left (thus turning the backlight off), you will notice how the noise suddenly goes away.

    Are there any other MacBook Pro owners with similar configurations which can hear the same noise? Or is my MacBook Pro faulty?

    What makes we wonder is what actually is causing this noise, since the LED backlight shouldn't have an inverter which would cause this noise, unlike a CCFL powered backlight.
  2. cmm26red macrumors regular

    Jan 29, 2008
    I am one of the users who is having a high pitched noise when in Vista that varies with the display brightness. In my opinion, you issue seems unrelated to what many others and I am experiencing. My noise emanates from the upper left hand side of the machine, right below the panel. This sounds like a GPU issue (hardware), however, looking at the motherboard courtesy of Anandtech, http://www.anandtech.com/mac/showdoc.aspx?i=3240&p=2 , there are very few components on the right side of the machine. When looking at these images, take into account that the motherboard is flipped and rotated 180 degrees from how it lays in the machine.
  3. rezonat0r macrumors 6502

    Nov 2, 2007
    Oh yes, I had this problem too. In my case it had the high-res Samsung matte screen.
  4. rezonat0r macrumors 6502

    Nov 2, 2007
    Agreed, I think this is a different issue. PeterKW, your issue is definitely the same as mine though. I am 90% sure that replacing the screen and only the screen would solve this problem.

    EDIT: Nope, it affects all 17" LED models regardless of glossy/matte. There is no fix at present.
  5. PeterKW thread starter macrumors newbie

    Apr 4, 2008
    Thanks for your quick replies!

    It seems I have an LG-Philips display.

    rezonat0r: Did you also get the noise under Mac OS X?
  6. rezonat0r macrumors 6502

    Nov 2, 2007
  7. PeterKW thread starter macrumors newbie

    Apr 4, 2008
    I've put a felt mat over the keyboard in order to figure out whether the noise comes from the screen or from the casing and indeed the mat doesn't cancel the noise, so like you said, this is probably a display issue.

    The noise seems to be stronger on the right side than on the left side.

    Guess I need to call AppleCare and send it in :(
  8. sporty macrumors newbie

    Feb 26, 2008
    I just got my brand new MPB and am having the exact same problems. The sound only goes away when I move the brightness to the far left, so basically turning it off.

    And same as you, I'm also having these problems in Mac OS X.

  9. rezonat0r macrumors 6502

    Nov 2, 2007
    Well I got my replacement 17" unit yesterday, and this one has the LG screen instead of the Samsung... and guess what, the noise is still there!

    So on a hunch I went back over to my girlfriend's machine which has the 17" Samsung and did another listening test. Turns out the noise IS in fact present on that unit as well; there is another quiet buzzing sound on that unit from the right fan that was masking the backlight noise when I first listened for it. Unfortunately I was wrong when I thought the other unit didn't have it.

    So, I've now heard this sound across 3 units and 2 screens... I'm afraid it's just something inherent to the LED backlighting or inverter used on the 17". At least the noise is quieter than the similar noise I had on my previous standard res 17" screen.

    I am pretty sensitive to sounds like this and I can live with it. I was just concerned that it was not normal and indicative of some other issue. The sound is only noticeable in a dead silent room and only if I have my head close to the screen and turned at a certain angle. Also, it varies depending on the backlight setting, almost completely disappearing on lower and higher settings and seeming to be "loudest" in the middle.

    It's not something I would notice at all if I weren't explicitly hunting for it, so for those that haven't noticed it, don't try to, you'll just drive yourself nuts. :cool:
  10. PeterKW thread starter macrumors newbie

    Apr 4, 2008
    Ah, too bad :(

    I sent my MacBook Pro in and I'll get a new one next week.

    In my case I heard the high pitched noise right from the beginning after turning on the MacBook Pro for the first time, I live in a rather quiet place so there's not much ambient noise here, which makes the noise even more annoying.

    What I really wonder is what is causing this, since an LED backlight doesn't require an inverter (unlike CCFL backlights), so it must be something else.
  11. rezonat0r macrumors 6502

    Nov 2, 2007
    Hmm, well the noise could vary in intensity from unit to unit, and it sounds like you may have gotten a noisier than average one. I didn't hear it on startup and had to hunt for it... good luck and do let us know how the replacement fairs.
  12. rezonat0r macrumors 6502

    Nov 2, 2007
    The plot thickens. I thought I'd be fine with the noise, but it's been about a week and I'm still actively hearing it when I sit down at the computer, even when I'm not thinking about it. So it's still an issue for me. Grrr.

    I called AppleCare, and surprisingly, the product specialist said they've had "a few" reports of the same problem. That's a good thing, and it means that yes, other people who haven't wrecked their hearing actually hear it too! So we aren't crazy.

    What the rep wanted to do was a "capture" where this unit gets sent back to an engineering dept to look at it further, and I get another replacement. I figured this was the best option and increased the chances that Apple might actually do something about it. Unfortunately, I believe this is a basic flaw and that the 3rd unit will have the same issue to some degree. Apple has historically dragged their feet on all the other noise issues that have plagued the MBP line, and I doubt this will be any different.

    Plus, the screen on this current unit is absolutely beautiful - statistically it's unlikely I'll get as good of a screen on the 3rd one. My plan at this point is simply to sell the unopened replacement unit and look elsewhere. :( I guess it's too much to ask to have a 17" LED backlit screen that looks good AND doesn't buzz in my ear. :rolleyes:

    PeterKW, you probably haven't gotten your replacement yet, but if you decide to break the seal on it, I'd be very curious to see if there's any difference with your new one.
  13. sporty macrumors newbie

    Feb 26, 2008
    Any of you tried installing Windows?

    I did and the problem is even way worse there. Noise is louder and it only goes away at full brightness. (noticed other threads regarding this)

    Annoying, very annoying.
  14. Sir Cecil macrumors 6502a

    Mar 31, 2008
    Has anyone who has experienced this problem used an external monitor with their buzzing MBP? Does the noise from the MBP persist?
  15. sporty macrumors newbie

    Feb 26, 2008
    I just tried that now. Connected my 30" LCD to MBP.

    In Mac OS X no real change, perhaps just a little little bit more quiet, but nothing drastic.

    In Windows: similar, perhaps a slight tiny change.
  16. Sir Cecil macrumors 6502a

    Mar 31, 2008

    How about in closed mode? Obviously not an ideal answer, but if it means one can work without the noise until Apple or someone else finds a fix, it's better than suffering the distraction in the meantime.
  17. PeterKW thread starter macrumors newbie

    Apr 4, 2008
    I got my replacement today and it also has the noise, pretty much exactly like the previous unit. The current unit also has the LG-Philips screen.

    I'm going to send it back and get a refund :/

    I believe it's a design issue which can only be fixed by e.g. changing the layout of the logic board and since apparently many people don't hear the sound this is probably not a very high priority item for Apple.

    The bad thing is that I haven't found a comparable notebook yet, which I could buy instead.
  18. rezonat0r macrumors 6502

    Nov 2, 2007
    I'm in the same boat. Very aggravating. My first instinct is to drop to the 15" and use the leftover $ for a big display. But my friend just got a 15" and it is plagued with the noisy headphone audio out, like so many others on here. The Air paired with a big screen would be nice, but it's pricey for something with old CPUs.

    This backlight issue should have been caught on day one if any decent QC was being done. I really don't know where to go at this point.
  19. sporty macrumors newbie

    Feb 26, 2008
    Hmm, haven't tried that. I already sent it back.

    Based on other responses I guess I need to really PRAY now. :)
    I wouldn't even mind if there was yellowing on the screen, as long as it's quiet. But I guess even that is a long-shot. :(
    I need a unit soon, but this noise is a no-go for my overly-sensitive hearing (it's actually causing me REAL headaches) ... :(
  20. PeterKW thread starter macrumors newbie

    Apr 4, 2008
    Same here, I'd be happy to hear about your experiences with the replacement unit. To me it seems this is a design flaw in the logic boards and thus affects all Penryn MBP's. So far I haven't found any evidence that there are actually Penryn MBP's around which don't have this noise.
  21. VincentPun macrumors member

    Oct 15, 2007
    I got the exact same problem. I also believe that is a logic board design problem.
  22. rezonat0r macrumors 6502

    Nov 2, 2007
    I don't think any of the 15" have this noise; at least I haven't seen any reports of it. Also, the 17" standard res (CCFL backlight) screens don't have it.

    It's something specific to the 17" LED backlight and how power is regulated to it, so the logic board could be culprit, or it could be the screen itself, which is where the noise shoots from.
  23. bcaslis macrumors 68020

    Mar 11, 2008
    I have to say that I'm usually very sensitive to noise. If there is any noise from my 17" LED display than it's quieter than the fan and disk noise. I've heard displays with whines in the past, but there isn't any on this machine. So I have to disagree with statements that they all have them or it's a design flaw.
  24. PeterKW thread starter macrumors newbie

    Apr 4, 2008
    There are multiple reports of this noise from 15" MPBs here:

    Not sure about the CCFL backlights, at least I haven't seen any reports yet.
  25. iToaster macrumors 68000


    May 3, 2007
    In front of my MacBook Pro
    Does it go away if you open photobooth? If so, looks like an idle processor, which is known to make a high pitched noise. Regardless of what it is, I wouldn't worry about it unless it's really annoying, but I have no idea what it could be...

Share This Page