HT204267: If your Mac won't turn on

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garconfrombalgowlah

Q: my imac wont turn on

my imac 2014 21.5inch model i5 when turning it on it starts up and then the apple icon shows on screen along with the loading or updating bar below it. It gets half way through and then turns off. Any ideas on how to fix this please? Thanks

iMac, OS X Yosemite (10.10.5)

Posted on Sep 2, 2015 10:40 PM

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Q: my imac wont turn on

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  • by Kappy,

    Kappy Kappy Sep 2, 2015 10:43 PM in response to garconfrombalgowlah
    Level 10 (270,295 points)
    Desktops
    Sep 2, 2015 10:43 PM in response to garconfrombalgowlah

    Reinstalling OS X Without Erasing the Drive

     

    Boot to the Recovery HD: Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears.

     

    Repair the Hard Drive and Permissions: Upon startup select Disk Utility from the main menu. Repair the Hard Drive and Permissions as follows.

     

    When the recovery menu appears select Disk Utility and press the Continue button. After Disk Utility loads select the indented Macintosh HD entry from the the left side list.  Click on the First Aid tab, then click on the Repair Disk button. If Disk Utility reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit Disk Utility and return to the main menu.

     

    Reinstall OS X: Select Reinstall OS X and click on the Continue button.

     

    Note: You will need an active Internet connection. I suggest using Ethernet if possible because it is three times faster than wireless and more reliable.

     

    Alternatively, see:

     

    Reinstall OS X Without Erasing the Drive

     

    Choose the version you have installed now:

     

    OS X Yosemite- Reinstall OS X

    OS X Mavericks- Reinstall OS X

    OS X Mountain Lion- Reinstall OS X

    OS X Lion- Reinstall Mac OS X

     

         Note: You will need an active Internet connection. I suggest using Ethernet

                     if possible because it is three times faster than wireless.