Tackle your Mac booting to a gray screen

FinderIconYosemiteXGiven the efficiency and convenience of sleep mode on Mac systems, it is often a rarity that we end up restarting our Macs. When we do, we expect it to boot to normal operation; however, sometimes a snafu may result in your Mac booting to a gray screen, and no further. Often such behavior happens because of a specific problem, such as a power outage, or the installation of a new software package, but regardless, if it happens there are essentially only a few things that you can do.

Testing your Mac

1. Safe Mode

First, reboot your Mac and hold the Shift key down immediately when you hear the boot chimes, in order to load into Safe Mode. This will bypass all but essential system software, so if a problem is with a third-party system extension, then this will suggest you need to tackle your software and add-ons to fix the problem.

Safe Mode will remove some caches and other temporary files, in addition to running a fix routine on your boot drive, which in themselves can sometimes fix the problem at hand; however, Safe Mode mainly just bypasses problems and does not fix them. Nevertheless, you can use it to get up and running, and be able to remove recently added software or make other configuration changes.

If Safe Mode does not allow your system to boot, then the problem is deeper in the OS configuration and drive setup.

2. Recovery Mode

Next, try booting your Mac to Recovery Mode by holding Command-R immediately when you hear the boot chimes at startup. This will load your system’s built-in recovery disk that has a minimal version of OS X installed. This drive’s contents cannot be tampered with under normal circumstances, so it should boot just fine if your Mac’s hardware is working properly.

If for some reason standard Recovery Mode is not working, then next try restarting your mac and forcing it to load Internet Recovery by including the Option key along with Command-R. Provided you have an active Internet connection, your system should download the ~650MB recovery mode disk image from Apple and then boot to it.

3. Target Disk Mode

Most Macs support a boot option called Target Disk mode, that allows your hard drive to be accessed as an external drive via Firewire or Thunderbolt. This mode only loads limited hardware components, so it is not a good way to test your Mac’s hardware; however, it can be used to test your hard drive. By attaching your system to another Mac, the drive should mount and become available, where you can use Disk Utility to verify and repair the system. You can also manually back up any files you may need.

If you cannot mount your drive in Target Disk mode, or find it is slow to access, then this indicates a problem with your drive and you might need to have your Mac serviced.

4. Hardware Tests

If you cannot get your Mac to load in Recovery Mode, then it is time to test its hardware for any detectable errors. To do this, reboot your system and hold the “D” down on your keyboard when you hear the boot chimes. To boot to the Internet-based hardware tests, do the same but hold Option-D instead. This routine will load and run Apple’s tests and ensure all hardware on your system is running as expected. If an error occurs, you will see a reference to it output on the screen; however, if not then it will indicate no errors are found.

Recovering your Mac

If any of the above tests fail to work, then you likely have a hardware problem that cannot be overcome on your own, and it is time to schedule a repair for your Mac. However, if you can access these modes without error, then you can perform any of the following approaches for fixing your system:

If Safe Mode works, uninstall recently added software or undo other recent changes that may have contributed to the problem. This can be done using official uninstallers that are distributed with programs, or by contacting developers for uninstall instructions. You can also access reputable troubleshooting resources to determine what exactly might be done for specific software errors.

If Recovery Mode works, then consider reinstalling OS X using the tools presented to you. Granted you can restore from a recent backup, but not knowing the reason for the hangup at boot means any number of recent backups may contain the faulty configurations that are causing the problem. On the other hand, reinstalling OS X should not overwrite your personal files at all, and only replace system software files. Provided your hard drive is in working order, this should get it to boot again.

Wipe and reinstall OS X if a basic reinstall does not work. To do this, first ensure you have a full backup of your system, and then use Disk Utility in Recovery mode to erase your hard drive. You might consider re-partitioning and formatting your drive, but at least erase it in full. Then return to the tools menu and again reinstall OS X from scratch. When done, you can use the OS X Setup Assistant to migrate your data and applications from your backups. This approach will ensure OS X is fully operational, and will copy files from your backups to your Mac in a way that is supported and should ensure the system remains functional.

6 thoughts on “Tackle your Mac booting to a gray screen

  1. FixMaX

    How to edit comments? To add…

    – Repair permissions.
    – Apple Disk Utility repair disk.
    – Leave at least 10% free space in disk.
    – Update Mac OS X and other software.

  2. Paul Bergsagel

    I believe you missed an important step, the use of cloning software. I use Carbon Copy Cloner to keep a cloned copy of my Mac’s Hard drive on an external hard disk. I clone this disk once a day. In a case were the Mac boots to a grey screen I am able to boot to the external drive which has a cloned copy of my hard drive. This lets me know if there is a hardware problem if the external drive will not boot my Mac. From this drive I am also able to run disk utility to verify the Mac’s drive. And finally if the drive needs repair and disk utility cannot repair it I can reformat the drive and clone the external copy of my Hard Drive from the external disk to my Mac’s Hard Drive.

    1. Topher Kessler Post author

      The article isn’t about preventative measures, but rather what to do if you encounter this issue without having contingency plans. If the problem is software-based, then a clone may also have inherited the problem and similarly not work. However, having a clone is definitely always a good idea.

      1. B. Jefferson Le Blanc

        That was the problem in my case. I had updated my clone before I knew I had a problem. That’s why, though Time Machine is not my favorite backup method, I use it. And if I had not, my whole system would have been toast, beyond recovery. You can’t beat redundancy. Multiple clones is another option.

  3. Strod

    Regarding restoring a backup, the article says that the backups themselves may include the change that is causing the inability to boot successfully.

    But if you are restoring from a Time Machine backup then you should be able to choose a backup date that predates the last time you booted your Mac successfully.

  4. Daniel Chaparro


    Apple has issued a Repair Extension Program for Video Issues. I was experiencing the same problem and had tired several solutions that worked for a short period of time, but ultimately I was unable to get my MBP up and running last night and brought it into an Apple store. They determined that my issues was in fact a video issue and qualified for free service.

    If you purchased a MBP between February 2011 and December 2013 and suspect that your MBP is experiencing the same issue, then check out the page URL above to see if your MBP qualifies for service.

    Here’s an excerpt from the page


    Apple has determined that a small percentage of MacBook Pro systems may exhibit distorted video, no video, or unexpected system restarts. These MacBook Pro systems were sold between February 2011 and December 2013.

    Apple or an Apple Authorized Service Provider will repair affected MacBook Pro systems, free of charge. See below for details on affected models and service options.


    An affected MacBook Pro may display one or more of the following symptoms:

    Distorted or scrambled video on the computer screen No video on the computer screen (or external display) even though the computer is on Computer restarts unexpectedly

    Products affected 15-inch and 17-inch MacBook Pro models manufactured in 2011 15-inch MacBook Pro with Retina models manufactured from Mid 2012 to Early 2013

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