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iMac i7 screen flicker

4589 Views 29 Replies Latest reply: Apr 21, 2012 1:17 PM by Marsue RSS
  • Motyoj Level 1 Level 1 (10 points)
    Currently Being Moderated
    Jul 17, 2011 5:46 AM (in response to g4going)

    I got mine a few days ago:

    Model Name:          iMac

      Model Identifier:          iMac12,2

      Processor Name:          Intel Core i7

      Processor Speed:          3.4 GHz

      Number of Processors:          1

      Total Number of Cores:          4

      L2 Cache (per Core):          256 KB

      L3 Cache:          8 MB

      Memory:          16 GB


    This morning I noticed a bit of a flicker and came to these boards and it didn't take 10 seconds to find others with the same issue. I have Apple care but that package hasn't arrived yet. Hope this goes away.

  • Gnube Calculating status...
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    Jul 21, 2011 12:12 AM (in response to Motyoj)

    I can confirm that this issue is not resolved with an update to OSX 10.7 (Lion)

  • MortgageGod Level 1 Level 1 (0 points)
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    Aug 9, 2011 9:56 PM (in response to Gnube)

    Call tech support and request the Firmware update for the ACD. It will take filling out some paperwork, but it seems to have fixed my problem.


    I too had the dreadded black screen off and on.



    24" ACD 2011 MBP 2.2 Quad i7

  • Gnube Level 1 Level 1 (35 points)
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    Aug 9, 2011 10:18 PM (in response to MortgageGod)

    Thanks for the reply MortgageGod.


    I do have a case open with support, my system has all firmware and OS updates applied. Apple are working on a resolution. Until that is made available in a future update I have no alternative but to use my old monitors whilst the ACD collects dust.

  • MortgageGod Level 1 Level 1 (0 points)
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    Aug 9, 2011 10:36 PM (in response to Gnube)



    Message was edited by: MortgageGod

  • Gnube Level 1 Level 1 (35 points)
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    Aug 9, 2011 11:00 PM (in response to MortgageGod)

    Ah right.


    I haven't heard of a new patch from my support case guy yet. I will whiz off an email to my case manager to check on that. I ran some test tools they sent me and returned the diagnostics logs etc last week; I expect that there area few issues for specific monitor builds etc - hopefully the build that works for you will suit my setup too.



  • Bruce Kieffer Level 1 Level 1 (145 points)
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    Aug 10, 2011 6:46 AM (in response to Gnube)

    This thread is about iMac flickering, not ACD. I got mine fixed. Took it in to my local Apple Store and they replaced the screen and brightness controller. Only problem is that took them a week to accomplish.

  • MortgageGod Level 1 Level 1 (0 points)
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    Aug 10, 2011 7:03 AM (in response to Bruce Kieffer)

    Yea I know, sorry. I figured that out when I answered my 2nd post, that is whay I deleted it.

  • tomacta Calculating status...
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    Aug 10, 2011 9:43 AM (in response to tomacta)



    It took the shop 15 days to get to my work order (part was in stock during this whole time), but they finally got to it and the problem is solved.


    They replaced the display. Everything is good in the world for now (except the economy).

  • Krag Level 2 Level 2 (215 points)
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    Sep 17, 2011 9:47 AM (in response to g4going)

    My 2011 Mini worked fine for 3 weeks, now flickering on startup for longer and longer periods until goes away.


    Obviously a Lion problem, we'll just have to wait for Apple  to fix it. If EVERYONE with a flicker called Apple support me thinks they'd get on it sooner than later.

  • skullcat Level 1 Level 1 (0 points)
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    Oct 3, 2011 6:34 PM (in response to g4going)

    I have this same problem -- intermittent flickering and once in a while, complete blackout.


    I can still hear fan running (or even a DVD burning) in background, but cannot wake up the screen. Forced to "sleep" (power button) and then the computer will wake OK (however forcing the computer to sleep interferes with some operations so it is not a good solution).


    This is my main workstation at the moment, so taking the computer in for a "fix" is not an option. I've been using the computer for about one year and until the past couple of weeks, this problem had NEVER occurred.


    My 27" i7 iMac is mid-2010

      Processor Speed:          2.93 GHz

      Number Of Processors:          1

      Total Number Of Cores:          4

      L2 Cache (per core):          256 KB

      L3 Cache:          8 MB

      Memory:          8 GB

      Processor Interconnect Speed:          4.8 GT/s

      Boot ROM Version:          IM112.0057.B00

      SMC Version (system):          1.59f2

  • freshlyground Calculating status...
    Currently Being Moderated
    Dec 6, 2011 10:27 AM (in response to g4going)

    I have a mac mini server I bought yesterday experiencing this same issue.  The flickering is driving me nuts.  I finally started pulling cables and the such and found that getting rid of the apple connector and using a HDMI to DVI cable has seemed to stop the issue.  It is too early to know if it is officially solved, but Ill keep you posted.

  • Gnube Level 1 Level 1 (35 points)
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    Dec 6, 2011 5:09 PM (in response to freshlyground)

    My flicker issue was on the 24" Apple Cinema Display (ACD) when using them on thunderbolt ports.


    Apple were able to identify the issue on my machine and created a firmware update for the ACD which has completely resolve the problem for me. If you are using an ACD on thinderbolt and are having flicker issues I'd recommend contacting Apple Tech Support to see if you need that monitor firmware patch.

  • Marsue Level 1 Level 1 (0 points)
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    Apr 20, 2012 1:13 PM (in response to g4going)

    I am having the flashing problem, too.  Very irritating.  It's like having someone take a flash photograph of me right into my face. I've scheduled a phone cal from tech support for tomorrow.


    27 " mid-2011 iMac

    AMD Radeon HD 6970M 2048 MB Graphics Card

    running Mac OS X Lion 10.7.3

    Hardware Overview:


      Model Name:          iMac

      Model Identifier:          iMac12,2

      Processor Name:          Intel Core i7

      Processor Speed:          3.4 GHz

      Number of Processors:          1

      Total Number of Cores:          4

      L2 Cache (per Core):          256 KB

      L3 Cache:          8 MB

      Memory:          16 GB

  • Marsue Level 1 Level 1 (0 points)
    Currently Being Moderated
    Apr 21, 2012 1:17 PM (in response to Marsue)

    I didn't have the flicker, but a flash (see my post above). I just had a call from Apple Support and we did the following:  We did:


    1. A PRAM reset: Power off the Desktop. Unplug the power cord from the bag and wait a couple of minutes. Re-plug in the Desktop. Immediately after pressing the "on" button, Hold down the following keys: "option," "command," "p," and "r." Continue to hold them down until you hear that third chime tone.  Then release them.  Shut the machine down again and re-boot normally.
    2. Open "System Preferences" under the Apple icon at the top left. Go to "Users & Groups." Click on your name, and then choose the "Log In Items" tab.  Unclick everything that you don't want to open or activate upon your start up.
    3. Because I was experiencing the flash mostly when I was on-line using Safari, the Apple technician suggested that if I continued to have difficulties, I should go to the Safari menu and click on "reset Safari." Unclick everything except "Save Name and Passwords" and "Remove other Auto-fill Text." then hit OK.

    So far no flashes!  But its only been a few minutes

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