sipos.endre.mark
Level 1 (4 points)
Notebooks

Q: blinking bug

Dear Apple Support

 

i have a 1 year old MACBOOK. The screen has a blinking or vibrating bug. It's in the top left corner, it looks like a blinking barcode. sometimes it goes away, but most of the time it's there. its only there when the Menu bar is visible ( e.g. when I'm watching a movie on full screen its not there, but when I'm browsing it is there. i tried to fix it by starting my mac while holding down option+ command + P + R, but it didn't help.

iMac, OS X Yosemite (10.10.5)

Posted on Sep 11, 2016 11:25 AM

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sipos.endre.mark

Q: blinking bug

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  • by Johann.B,

    Johann.B Johann.B Sep 12, 2016 3:48 PM in response to sipos.endre.mark
    Community Specialists
    Sep 12, 2016 3:48 PM in response to sipos.endre.mark

    Hello sipos.endre.mark,

     

    Thank you for using the Apple Support Communities!

     

    It is my understanding you are experiencing an issue in the top left corner of your MacBook.  I know how important it is to have a properly working screen and will be happy to help you any way I can.  It looks like you have already done a PRAM reset.  That is a good place to start.

     

    The next thing I would do is backup everything that is on the computer. Nothing I am going to suggest should cause any data loss, but it is always a good idea to have a backup.  Your computer has software on it called Time Machine.  It is fantastic software for backing up your computer.  Information on how to use Time Machine is available here:

    Use Time Machine to back up or restore your Mac.

     

    Once you have a backup,  there are some steps that can be used to isolate what is causing the problem.  They include starting in safe mode and testing in a new user account.  First, let's try safe mode.  Here is how to start the computer in safe mode:

    1. Choose Apple menu > Shut Down.
    2. After your Mac shuts down, wait 10 seconds, then press the power button.
    3. Immediately after you hear the startup tone, hold down the Shift key. You should press the Shift key as soon as possible after you hear the startup tone, but not before.
    4. Release the Shift key when you see the gray Apple logo and progress indicator.

    To leave safe mode, restart your Mac again, but don’t hold down any keys during startup.

    The above information about safe mode can be located here:

    OS X Yosemite: Start up in safe mode

     

    If the problem does not occur when in safe mode, then there is something being started during a regular start up that is causing the issue.  To solve this, try removing login item and startup items.

    OS X Yosemite: Open items automatically when you log in


    If the problem still occurs in safe mode, then you will want to test in a test user.  Instructions for this procedures are located here:

    How to test an issue in another user account on your Mac

     

    If the problem does not appear in the test user account, then there is something in the original user account that is causing the problem and further probing will be needed to determine the cause.

     

    Take care, and thanks for visiting the Apple Support Communities.