I use top-notch MBPRO15 Late 2011 with the latest OSX and all the recent updates installed. I had booting problems before which I managed to solve through command+option+P+R. I'm not sure what exactly caused the problem, but it helped a couple of times. But starting from yesterday I'm failing to make it boot whatever I do with it.

So I'm having this:

  1. I turn on the Mac
  2. Chimes go as expected and the initial login screen appears
  3. I put my credentials and booting progress bar starts up
  4. After like 30-60 secs the progress bar disappears leaving me only with a grey screen.
  5. Two options possible afterwards (i) the screen stays grey for as long as I wait or (ii) the mac reboots leading me to the initial login screen.

When try to go to the Troubleshooter with command+R the sequence is exactly the same. Instead of the Recovery mode I get a frozen grey screen.

If you need any more information to localise the problem please ask.

  • 1
    Did you try single user mode (cmd-s) or Internet Recovery mode (alt-cmd-r)?
    – klanomath
    Feb 13, 2015 at 9:39
  • @klanomath no not yet. will do today and let you know! thanks!!
    – LoomyBear
    Feb 13, 2015 at 9:40
  • 1
    @LoomyBear Did you install the latest SimCity in the last couple of day? A client of mine had similar problems after installing it from obscure sources. After booting to single user mode, then just entering 'exit' to boot to Aqua, downloading Onyx (or Yosemite Cache Cleaner), opening it, deleting all caches (System/Lib/User's cache) and rebooting i got it fixed.
    – klanomath
    Feb 13, 2015 at 9:48
  • 1
    @LoomyBear Answer added
    – klanomath
    Feb 14, 2015 at 19:52
  • 1
    The symptoms show that you MBP has a GPU problem as almost all 2011 MBPs. Please backup your files regularly. Nobody knows when your Mac will stop working. Search for 2011 MBP GPU for more information.
    – Pratik
    Feb 16, 2015 at 7:26

4 Answers 4


You may find these links of some interest:


  • hey man! that's exactly what I'm having and mine mbp is late 2011. I'll go and try to push it to a local apple store. Thanks so much bro!!
    – LoomyBear
    Feb 24, 2015 at 22:10
  • Answers on Ask Different need to be more than just a link. It's okay to include a link, but please summarize or excerpt it in the answer. The idea is to make the answer stand alone.
    – nohillside
    Feb 24, 2015 at 22:14
  • I went to Apple Store after all and they confirmed the hardware problem you mentioned. After a week of repairing I'm back in business. Free of charge and any hassle. Thanks again for pointing that out!
    – LoomyBear
    Mar 16, 2015 at 13:59

To fix this try the following:

  • boot to internet recovery mode by pressing cmdaltR immediately after the start-up chime. Depending on your internet connection the boot process may take several dozen minutes.
  • open Disk Utility, choose your main volume, verify and repair it if necessary

    enter image description here

  • if you had to repair errors just repeat the step to recheck that all errors are gone
  • reboot to your main drive
  • if the problem persists boot to single user mode by pressing cmdS after the start-up chime to circumvent the lockout.
  • after booting is done just enter 'exit' at the prompt to start to the common Aqua interface.
  • download Onyx or Yosemite Cache Cleaner
  • start Onyx
  • clean system/user caches

    enter image description here

  • or start Yosemite Cache Cleaner
  • clean system/user caches

    enter image description here

    ** "System" is the name of the start volume in my VM. Your volume name may be different.

  • restart your Mac


Try booting into Single User mode, hold Command - S as system starts turning on.


Try Safe Boot by holding the shift key when you hear the startup chime. As mentioned by klanomath, run Onyx to clear system and user cache files, and also use it to repair permissions (selecting the option to check home folder permissions).

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