27" iMac quad buzzing/screen brightness issue

Discussion in 'iMac' started by thatdarnfish, Jan 24, 2010.

  1. thatdarnfish macrumors regular

    Joined:
    Sep 23, 2004
    Location:
    New York
    #1
    I recently noticed a buzzing sound coming from the top left of my new iMac. Unlike some of the other posts I have seen here, the buzzing actually decreases when I put the brightness down on the monitor. Anyone else have this issue or know of a fix? Thanks in advance...
     
  2. WilliamG macrumors 604

    Joined:
    Mar 29, 2008
    Location:
    Seattle
    #2
    I notice it on mine, too, but only if the room is 100% silent. It's coming from the top of the display, perhaps the top left. I don't hear it at normal seating distance in my room in downtown Seattle (ambient sounds outside 24/7), and yes, unlike CCFL displays where the buzzing goes away as you hit full brightness, on this model it actually increases the sound!

    I'd say if you can hear it easily (which is VERY subjective based on your hearing), then perhaps it not normal, but based on your description, what you're hearing is the unfortunate buzzing/electrical sounds that accompany many electronic devices these days, it seems.
     
  3. thatdarnfish thread starter macrumors regular

    Joined:
    Sep 23, 2004
    Location:
    New York
    #3
    Thanks for your reply. Actually, I just came back from dinner out and the sound is gone. I was playing my guitar through garageband this morning and that usually taxes the CPU a lot. I'm wondering if that made the iMac super hot and caused the noise. In any event, it seems to have been short lived, thank goodness!
     
  4. WilliamG macrumors 604

    Joined:
    Mar 29, 2008
    Location:
    Seattle
    #4
    Well, I'm glad you figured it out! And that means you haven't noticed the buzzing that all iMacs make. You really have to have the most incredibly sensitive ears in a COMPLETELY silent room to hear it (or just put your ear to the top of the screen, lol!).
     
  5. ordiple macrumors newbie

    Joined:
    Feb 8, 2009
  6. thatdarnfish thread starter macrumors regular

    Joined:
    Sep 23, 2004
    Location:
    New York
    #6
    Bump....


    It's back now. I've found it makes the noise: a. when I have my space heater plugged into a different socket in my room, b. when I scroll through windows, and c. when the computer gets hot. This video is a good example of what I'm hearing: http://www.youtube.com/watch?v=jXyH1XGFFck

    Anyone else have this problem? Am I just being too sensitive inasmuch as machines normally make this noise?
     
  7. Yakuza macrumors 6502a

    Yakuza

    Joined:
    Jul 24, 2007
    Location:
    Lisbon, Portugal
    #7
    ohhh great...that's just great.

    Coming back with bad news. I've just recieved my i5, after a full month of nail biting and ripping hair, there she was the most beautiful machine.

    And after reading countless threads about yellow tinge and flickering, the fear was high but in the end, a big NO to all.

    The problem i'm having is this mind grinding buzzing / static or electric kind of sound in the top bottom.

    When does it disappear? when it's full bright, although there might be a slight remaining buzzing. Would i be ok with this? Maybe, if it wasn't for the fact that i can't stand this much bright in this or other monitor.

    Resolution: i reduce the brightness, BUT the buzzing / static / electric kind of sound starts right away.

    I guess the only thing to do is send it back, isn't it?

    :( what a bad, bad luck

    PS: it fades away every time i scroll up/down
     
  8. Yakuza macrumors 6502a

    Yakuza

    Joined:
    Jul 24, 2007
    Location:
    Lisbon, Portugal
    #8
    UPDATE

    I've change socket, different plug in the same socket outlet extension with no success. the humming buzzing zoom zzoom is still there.

    Any ideas guys?
     
  9. thatdarnfish thread starter macrumors regular

    Joined:
    Sep 23, 2004
    Location:
    New York
  10. nickv1980 macrumors newbie

    Joined:
    Jan 30, 2010
    #10
    Both my week 51 machines Imac i5 had this problem both sent back it was quite loud concidering my imac is right next to my bed it irritated me alot :mad:

    The Buzzing problem (upper left hand corner) only became apparent once the imac got hot and :

    1: Lowered the brightness down a few bars

    2: Let the display dim before sleep

    Things that stoped the buzzing

    1: Leave the computer at an eye burning brightness level

    2: Turn off power saving before sleep

    3: Turn off imac for an hour and restart (only temp fix until it heated back up)

    Another thing that i did find with the first machine is that if u lowered the brightness level for a decent period of time the buzzing stoped to an extent (still there but alot softer)

    Second machine this was not the case it was louder and constant :(

    Went into myers to check out there display C2D 27 it had the buzzing too. I was starting to think it was normal until i read a few storys of ppl having the same symptoms which turned out to be a power supply issue and repaired .

    Theres a youtube vid about above ^^^^
     
  11. Yakuza macrumors 6502a

    Yakuza

    Joined:
    Jul 24, 2007
    Location:
    Lisbon, Portugal
    #11
    I swa a video on youtube indeed, can remember now if it was this one, it was someone in a kitchen with the imac and then he increased the brightness and go and record the sound, dim down the brightness and went up the imac to record the sound again, it's exactly the same kind of sound.

    Just going to give it one more day of running, and then call Apple Store to replace it:(
     
  12. adammjenkins macrumors member

    Joined:
    Dec 15, 2009
    Location:
    West Virginia
    #12
    Screen Buzz Noise

    Hello Everyone,
    I just thought I'd report another one of these incidents. I just noticed that my week 51 iMac started buzzing when the display went to sleep. I am able to replicate this issue, but it seems like the issue is much more prominent while the computer is warm. I noticed this issue particularly after encoding a movie. With the display off, it almost seems as though a fly is trapped inside my monitor. It's a persistent buzzing noise. When I wake the screen back up, however, the buzzing turns into a very high-pitched noise... almost like a dog whistle or one of the hearing tests. This issue is also prompted by using the keyboard to increase/decrease the screen brightness. At approximately 50% brightness, the buzz or high-pitched sound begins (depending on which direction I am going with the brightness). I called Apple, and because I had already narrowed the issue down by some basic Googling and was able to describe the sounds to them, they agreed that the problem needed to be taken care of. The closest Apple store to me is 2+ hours away, so they have agreed to complete replace the unit, despite being out of the 30 day period. I guess they make exceptions if you live in a place that isn't fortunate enough to have an Apple store.

    Here's to hoping that my replacement is free of some of the other more prominent issues (flickering, yellow tint, dead pixels, loud hard drives, etc.)
     
  13. Yakuza macrumors 6502a

    Yakuza

    Joined:
    Jul 24, 2007
    Location:
    Lisbon, Portugal
    #13
    i guess this buzz/high pitch noise is more common then we think. i hope my next one asn't got the buzz/high pitch sound
     
  14. tmorterlaing macrumors member

    Joined:
    Jul 14, 2008
    #14
    Buzzing fixed from top left of computer

    Hi everyone, I work at an Apple Reseller, and have had about 5 macs of my own, and I can tell you that on the slightly more powerful macs if it is buzzing when the screen is darkened etc it seems to buzz whilst it cools down, but when it gets cooler it dissipates until you can not really hear it at all. So speed up the process you could get 'smc fan control' and speed up the CPU and HD fan maximum for a few minutes whilst the computer isnt doing anything, then turn them down again, and try again. If there is no difference or the buzzing gets worse then yeah, possibly give apple a ring! :D
     
  15. pionata macrumors 6502

    Joined:
    Oct 12, 2005
    Location:
    Montreal
    #15
    Mine is totally quiet, working at 40-50% brightness.

    That sort of stuff happens with electronic, no component is identical.
     
  16. WilliamG macrumors 604

    Joined:
    Mar 29, 2008
    Location:
    Seattle
    #16
    I can hear a slight electrical noise from the top right of my iMac i7 if I get close to it in a DEAD silent room, but that's normal I'd say. I doubt I'd be able to hear it if I didn't have my SSD in there. The computer is so much quieter in general without a spinning disk.

    But, technically speaking, no iMac is completely silent.
     
  17. pmac5150 macrumors newbie

    Joined:
    Jan 14, 2010
    Location:
    Midwest
    #17
    My week 7 machine has the 'dim buzz' - goes from noticeable if the machine is idle to very annoying if several applications are open. My week 5 machine had no noise whatsoever. Apple is sending me machine #3 - hopefully 3rd time is the charm...
     
  18. FLHX Guest

    #18


    I have the exact issue you describe, but it comes and goes. Sometimes it is very noticeable, and sometimes not.

    When it is noticeable, turning down the brightness has a direct effect on the sound. The dimmer the screen, the less buzz.

    But, I'd say about 60-70% of the time, I have no buzz at all.
     
  19. blink1225 macrumors newbie

    Joined:
    May 28, 2010
    #19
    My Fix

    Hey,
    I had this same problem with my 21" iMac, that I just bought from Best Buy. I read through your thread, and nothing really helped me so I called Apple. Apple was useless, so I took it back to Best Buy and they were very helpful, and got me a new iMac right away.

    I have plugged the new one in and haven't detected the loud buzz when bringing brightness down and up like on the previous computer. I'd suggest that if you have bought it recently, go to the Apple store or wherever you bought it, and get a new one.

    Also, if my problem comes back in the next week or so, I'm not going to bother with Geek Squad at Best Buy; I am going to head directly over the Apple store and tell them to TEST it and make sure it's working, because if this happens 3 times that's just wrong, what's even more wrong is Apple is completely aware of this.


    Anyway thought my input and all the steps I went through this morning might help others having the problem, good luck!
     
  20. gurton macrumors newbie

    Joined:
    Jan 1, 2011
    #20
    Solution found (for me)

    I've had the same problem and it came and went. It was even noticeable when I moved the mouse around.

    I did a lot of searching around but ended up finding the solution by accident. The problem, it turns out, didn't have anything to do with my screen. It was a fluorescent lamp plugged in to the same circuit as my computer. It was actually on the other side of the room but it creates interference in the AC power that conflicts with the power supply in the computer. Somewhat similar to what makes some car stereos buzz when driving.

    I have played around with it since and changed my desk lamp to a CFL bulb and even though it was plugged in directly beside my computer it didn't make the noise. It turns out just some fixtures do it, and from what I can tell, ones with a dimmer switch are the worst. So, I would check to see if you have your computer plugged into an outlet that is on the same circuit as a light. Even an overhead light such as above a dining room table. It sounds weird, but it depends on how your house is wired because that light (or heater as one poster mentioned) doesn't even have to be in the same room. So just changing the plug won't help if that other plug is still on the same circuit!

    Surge protectors may help but unfortunately you may have to go to a more expensive current modulating power bar like the ones made for high end stereo equipment.

    For me, it was just a matter of moving a lamp. I hope this helps someone out there.
     

Share This Page