Late 2012 iMac - clicking/static sound?

Discussion in 'iMac' started by rittchard, Jan 4, 2013.

  1. macrumors 6502

    Aug 12, 2007
    Has anyone else noticed a really subtle/light clicking or static-type of sound coming from their iMac? I've pretty much ruled out everything (external drives, speakers, etc) but the unit itself. It's not really that loud, but if there are no other sounds I'll hear it occasionally and it is kind of bothersome.
  2. macrumors regular

    Jun 11, 2012
    Lima, Peru
    Yes I hear it too, I have no idea what is it though. But it isnt as annoying as the sound i get when the street lights go on. They kind of pollute my power system and my imac starts to make this buzzing sound, it isnt really loud but it is loud enough to be annoying.. I cannot really blame apple coz it doesnt matter if i get a replacement, it will still make a noise because of my dirty power. From what I've read it is not really harmful for the computer, it is just annoying.

    The sound comes from the bottom left of the computer right? Thats where the PSU is located.
  3. macrumors newbie

    Jan 10, 2013
    Devon, UK
    I have the same annoying static sound, it alternates from the bottom left and sometimes right corners and is more noticeable when I put the display to sleep or wake up. I phoned apple and received a replacement only to get the exact same noise.
  4. macrumors member

    Sep 21, 2007
    I've had this on my original and replacement. Definitely caused by the display brightness change.
  5. macrumors regular


    Mar 19, 2012
    PERTH, Australia
    Guy with street light problem I would ASAP get a UPS,
    To filter the power and protect from surge and Brown outs ..

    before something happens !!!

    If you get a UPS this should stop this issue from happening .

    I Can't imagine it's good for the computer
  6. macrumors 6502

    Mar 15, 2008
    I've got the same thing, probably something warming up - wouldn't worry about it.
  7. macrumors regular

    Nov 9, 2006
    New York
    I have the same thing on my replacement. My original unit did not have this issue but was plagued by a yellow and unevenly lit screen.

    I notice that it's more apparent when the screen brightness is low but it still happens when it's almost all the way up. I'm returning my replacement because of this and because the screen is also having an issue with image retention.

    I wouldn't just accept it as normal. Considering that my original unit did not have this issue I'm pretty sure that it's not suppose to happen.
  8. macrumors newbie

    Feb 2, 2013
    same static issue

    I just got a Late 2012 iMac, fully loaded, and have the same issue when the display brightness changes: Left-Right alternating static "ticks". i tried 3 different surge protectors and same issue happens with all 3.

    very unnerving because i wonder if there are any components that are slowly getting damaged as a result? good thing i got applecare! :rolleyes:
  9. macrumors member

    Dec 14, 2012
    Phoenix, Az
    For real had a customer with a blown power supply in there 27" iMac :( because of that
  10. macrumors regular

    Jan 14, 2013
    Melbourne, FL
    All the times I've heard people refer to a humming, static of buzzing sound, especially when they've ruled everything out, it winds up that they either had dirty power, or they were running a Back-UPS unit that wasn't compatible with Active PFC power suplies. With PFC power supplies, like the iMac has, you absolutely must run a Pure Sine Wave Back-UPS unit. Or else you'll get that humming. Also, most of the units, like the one I use, the CyberPower CP1350PFCLCD, have an AVR feature, that conditions, and regulates the power voltage without using the battery, which takes care of brownouts and such. You'd be surprised how much stuff can affect your home's power. In my house, if I turn on my laser printer or space heater in the same room, on my Back-UPS unit, I notice the input voltage drop quite a bit. Sometimes to the point where the Back-UPS unit would kick in for a second.
  11. macrumors 604

    Mar 29, 2008
    I'm not running a pure sine wave UPS and have never had an issue like this... I don't think you can blame the UPS in every case. Perhaps some cases, but you absolutely don't need a pure sine wave UPS.
  12. macrumors newbie

    Mar 4, 2013
    I have the same problem. Noticed it on my new 27inch imac (late 2012), sent it back and have same issue with the replacement. Not impressed for such an expensive computer
  13. macrumors newbie

    May 5, 2013
    Has anyone noticed the ticking starts if you dim the screen down to about 4 bars or less? I have this same issue on my late 2012 model 27" with the 1tb fusion and if I brighten the screen the sound stops.

    Discussed with AppleCare and they hadn't heard of this. Took it into the Apple shop and they cannot hear the issue when they dim the screen. They could only hear the fan and hard disk. They waited till the shop was closed then listened to it in a quiet room.

    As I didn't notice the issue for about 3 months (can't remember if I must have had the screen brighter) I'm told multiple times they would want to repair first, however they can't hear the issue so told me to come and collect it.
  14. macrumors 6502


    Jul 8, 2011
    As mentioned earlier in the other thread, I've not heard that strange static noise from the lower left corner for a few weeks now. I imagine it was, as someone mentioned, the tape holding the screen on and after x amount of use it's finally settled. Regardless of what it actually was, it's gone now!

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