frawarrior

Q: iMac graphics issue

Hi I have an iMac mid 2011 with Sierra installed. I'm experimenting an issue during the startup. When the progress bar reaches 1/3 of the total, it stops and appears a colored bar on the screen, and immediately later the screen goes black for a second, then come back to the progress bar screen and the Mac ends the startup successfully however. I've attached the photo where the colors bar appears. Thank you,    FrancescoScreen.jpg

iMac, OS X El Capitan (10.11.6)

Posted on Sep 27, 2016 2:34 PM

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Q: iMac graphics issue

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  • by jeremy_v,Helpful

    jeremy_v jeremy_v Sep 29, 2016 7:44 AM in response to frawarrior
    Community Specialists
    Sep 29, 2016 7:44 AM in response to frawarrior
    Howdy frawarrior,

    Thanks for using the Apple Support Communities!

    I understand from your post that on initial boot, your Mac will get stuck on the Apple logo screen along with colored bar, but then it will restart normally on its own.  To help get this issue resolved, I'd like you to please boot to safe mode, and then restart your computer normally.  Please report back with what happens:

    Starting up in safe mode

    Follow these steps to start up into safe mode.

    1. Start or restart your Mac. 
    2. Immediately after you hear the startup sound, press and hold the Shift key.
    3. Release the Shift key when you see the Apple logo appear on the screen.

    After the Apple logo appears, it might take longer than usual to reach the login screen or your desktop. This is because your Mac performs a directory check of your startup disk as part of safe mode.

    To leave safe mode, restart your computer without pressing any keys during startup.

    Try safe mode if your Mac doesn‘t finish starting up

    Take care.
  • by frawarrior,

    frawarrior frawarrior Sep 29, 2016 11:05 AM in response to jeremy_v
    Level 1 (4 points)
    Desktops
    Sep 29, 2016 11:05 AM in response to jeremy_v

    I started in safe mode, then reboot but the problem is still there. Maybe there is a problem with the graphic card? Someone says this is a not critical problem and I should not worry about this. Thank you

  • by Allen A,Helpful

    Allen A Allen A Sep 30, 2016 5:48 AM in response to frawarrior
    Community Specialists
    Sep 30, 2016 5:48 AM in response to frawarrior
    Alright, thanks for trying that out.  Next, we'd like to reset the SMC and NVRAM on your iMac, and see if it continues:

    Reset the SMC on Mac desktop computers

    Follow these steps for iMac, Mac mini, Mac Pro, and Xserve.

    1. Shut down the Mac.
    2. Unplug the power cord.
    3. Wait 15 seconds.
    4. Plug the power cord back in.
    5. Wait 5 seconds, then press the power button to turn on the Mac.
    Reset the System Management Controller (SMC) on your Mac

     

    Resetting NVRAM

    1. Shut down your Mac.
    2. Locate the following keys on the keyboard: Command (⌘), Option, P, and R. 
    3. Turn on your Mac.
    4. Press and hold the Command-Option-P-R keys immediately after you hear the startup sound.
    5. Hold these keys until the computer restarts and you hear the startup sound for a second time.
    6. Release the keys.

    After resetting NVRAM, you may need to reconfigure settings for speaker volume, screen resolution, startup disk selection, and time zone information.

    How to Reset NVRAM on your Mac

    Cheers.
  • by frawarrior,

    frawarrior frawarrior Sep 30, 2016 5:49 AM in response to Allen A
    Level 1 (4 points)
    Desktops
    Sep 30, 2016 5:49 AM in response to Allen A

    I'va done both the resets multiple times, but the issue is still there :/

  • by becky_s22,

    becky_s22 becky_s22 Sep 30, 2016 9:54 AM in response to frawarrior
    Community Specialists
    Sep 30, 2016 9:54 AM in response to frawarrior
    Hey frawarrior,

    Thank you for using the Apple Support Community. Due to the nature of your issue or question you may find more information by using another one of Apple's support resources - https://getsupport.apple.com/GetproductgroupList.action

    Take care.