powerover

Q: iMac (Mid 2011) stuck in restart loop

My Mid 2011, 27" iMac is caught in a restart loop. On start-up, the boot progress bar gets 1/3 full before the system goes to a blank gray screen then restart itself. It will continue this cycle unless I manually shut the machine off using the button. The cycle takes about 5 minutes.

 

  • Reset of PRAM did not help
  • Trying to boot into safe mode gives me a blue screen (see below). Same with recover disk.
  • Disk verifies okay via fsck and by using thunderbolt target disk mode with my MacBook.
  • Trying to boot into my Bootcamp partition hangs after the Windows animated logo goes away, leaving a black (lit) screen.

 

Thanks for the help.

IMG_2856.jpg

iMac, OS X Yosemite (10.10.3), Mid 2011, 27"

Posted on Apr 9, 2015 7:59 PM

Close

Q: iMac (Mid 2011) stuck in restart loop

  • All replies
  • Helpful answers

  • by Kappy,

    Kappy Kappy Apr 9, 2015 8:05 PM in response to powerover
    Level 10 (271,328 points)
    Desktops
    Apr 9, 2015 8:05 PM in response to powerover

    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. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.

     

    Reinstalling OS X Without Erasing the Drive

     

    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 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.

     

    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.

  • by powerover,

    powerover powerover Apr 9, 2015 8:17 PM in response to Kappy
    Level 1 (0 points)
    Apr 9, 2015 8:17 PM in response to Kappy

    Thanks for the quick reply. Booting from the Recovery HD gives me the blue screen though. it doesn't get all the way to a successful startup.

  • by Kappy,

    Kappy Kappy Apr 9, 2015 8:28 PM in response to powerover
    Level 10 (271,328 points)
    Desktops
    Apr 9, 2015 8:28 PM in response to powerover

    The HDD may be failing. Your model came with Snow Leopard installer discs. Try booting from the Snow Leopard installer DVD. If you get the same results then make a Genius Appointment and take it in for service.

  • by Linc Davis,Solvedanswer

    Linc Davis Linc Davis Apr 15, 2015 1:01 PM in response to powerover
    Level 10 (208,000 points)
    Applications
    Apr 15, 2015 1:01 PM in response to powerover
  • by powerover,

    powerover powerover Apr 15, 2015 1:05 PM in response to Linc Davis
    Level 1 (0 points)
    Apr 15, 2015 1:05 PM in response to Linc Davis

    Linc, you're a life saver. Apple agreed to replace the video card after a 10-minute visit to the Genius Bar... I had to drive two hours to get there, but well worth it. I was actually only two months away from the 4-year cutoff date.

     

    Thanks!