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  1. #1

    Member Since
    Aug 05, 2013
    Screen freezing/pixelating when I power on my iMac 24
    If anyone can help, I'd appreciate it. I powered on my iMac 24 (purchased in 2008) the other day and the entire screen pixelated (reds and purples), then just froze. I cannot do anything. If and when it fixes itself, I can click a user but that is as far as I can go. I tried using a different outlet, which worked for about an hour. The above problem occurred again. My Apple warranty has expired. I am running all current, up-to-date software, no upgrades or anything special. Any clue as to what it could be would be a great help! Thanks in advance!


  2. #2

    chscag's Avatar
    Member Since
    Jan 23, 2008
    Keller, Texas
    2017 27" iMac, 10.5" iPad Pro, iPhone 6s+, iPhone 7+, Numerous iPods, High Sierra
    It sounds like it may have something to do with the graphics card in your iMac. I'm not certain if your model has a separate graphics card or if it's integrated within the logic board.

    Try starting up your iMac in safe boot mode to see if the same thing occurs. Press and hold down your shift key as soon as you hear the bong sound and continue holding it until you get the spinning circle. You might also want to try a SMC reset: Shut down your iMac and remove the AC plug from the power outlet. Let it sit for around 5 minutes or so and then plug it back in and reboot.

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