Previous 1 2 Next 22 Replies Latest reply: Oct 2, 2012 10:12 PM by baltwo
tysteel Level 1 Level 1 (0 points)

After doing a software update, my Mac Pro got stuck on the gray screen after restart (seems like a very common problem recently). I am able to boot into safe mode by holding shift (only works like 10% of the time) and verified permissions. It says I need to repair my disk, but i can only do this by booting from my install disk.


However, I can not boot from my install disk. It gets stuck at the gray screen every single time.


I have done everything recommended in this post with no success:


Am I screwed here? So irritated that this all happened because of Mac's own software update. I have wasted HOURS troubleshooting and it looks like my only option is to pay to have it serviced.


Any help is appreciated.

  • BGreg Level 6 Level 6 (17,500 points)

    This sort of thing can be really annoying ....


    I didn't read all the steps in the note you referenced ... here is the Apple note addressing that problem.


    When you insert your OS X DVD, have you tried booting while holding the alt/option key down? That should present you with a menu of valid volumes to boot off of, one of which should be the OS X DVD.

  • baltwo Level 9 Level 9 (61,985 points)

    Zap the PRAM and Reset the SMC, then try booting with the install disc again.

  • tysteel Level 1 Level 1 (0 points)

    Thanks for the suggestions. I have reset the PRAM & SMC with no success. I have attempted to boot from the install disc several times by holding option at startup. I am able to select the DVD to boot but always end up back at the gray screen.



  • roam Level 6 Level 6 (13,560 points)

    Have you successfully booted form the Install disk before?

    Is it the original 10.6 disk that came with your Mac Pro, or a retail DVD you bought later to upgrade to 10.6?

    Do you have a cloned copy of your Mac on an external drive? If you do, you could boot into that and use that copy of Disk Utility to repair your drive.

  • tysteel Level 1 Level 1 (0 points)

    This is indeed a retail DVD that I bought to upgrade and not the original disc. I have tried booting with both discs.


    I don't have a cloned copy. How do I clone to an external disc?

  • roam Level 6 Level 6 (13,560 points)

    I don't have a cloned copy. How do I clone to an external disc?

    A clone is a copy made from a functioning Mac using clone software like CCC or SuperDuper!. You say you can boot into safe mode#. This is a bit unconventional, but you could try the following; you will need a functioning external hard drive, formatted as Mac OS Extended (Journaled) with a GUID partition map. If these details are elusive or vague to you, research this yourself beforehand.


    With a functioning external harddrive, see if you can download, and install the SuperDuper applicaton, in the Applications folder  and use it to make a copy (ie a clone) of your HD onto the Ext. HD. When all finished restart and hold down the Option key to give you the chance to boot into the external hard drive  clone*. If that is possible, then you can run its Disk Utility and perform a Repair Disk on the internal Macintosh HD, and hopefully correct whatever error exists.


    #Being able to boot into safe mode suggest there may be some software being loaded in normal mode that is causing the problem, but is difficult to diagnose. What is Safe Boot, Safe Mode?


    *if at this point it does not boot, there is not much more to try.


    Another variation, more straight forward would be to use Disk Warrior, although expensive, it is a good disk utility that may resurrect your boot process, but it is expensive, and it all depends on whether your Mac can boot into it as well. If it can't see it you would be facing the same problem.


    What was the update you did that lead to this?


    Message was edited by: roam

  • tysteel Level 1 Level 1 (0 points)

    My external hard drive is USB, so apparently this option won't work unless I buy a firewire drive.


    I updated iTunes and Security. Not exactly sure which versions, but they were the most recent.


    Looks like I am off to the service center.....

  • roam Level 6 Level 6 (13,560 points)

    Intel Macs can boot from USB, so you could still do it, but taking it in is a good idea also.

    Still when you get it going again, having a backup is a sensible move, primarily to save your data. The suggestion to use it to run Disk Utility is a secondary benefit / technique.


    Starting from an external USB storage device (Intel-based Macs)

  • tysteel Level 1 Level 1 (0 points)

    Thanks for your help roam. Here is where I am at now:


    Lugged the Mac Pro to the Apple Store. After about an hour, the Mac Genius seemed to guess that I needed a new hard drive since we weren't getting any results.


    I ended up buying a Seagate SATA hard drive.


    While booted in safe mode, was able to format disk (Mac OS Extended Journaled) and clone using SuperDuper!. The exact thing happens on the new hard drive. It will not boot. So, there must be something written somewhere preventing startup that got transfered, no? Or perhaps there is a trick to cloning I am missing?


    The new drive is completely visible and functional when I am in safe mode on the alleged broken drive.


    Thought I would try booting into safe mode on the new drive and repairing the old disk, then redoing the clone. However I can not even boot into safe mode.

  • baltwo Level 9 Level 9 (61,985 points)

    Does it boot normally on the clone?

  • tysteel Level 1 Level 1 (0 points)

    No the clone will not boot. Gets stuck on gray screen.

  • baltwo Level 9 Level 9 (61,985 points)

    What about a safe boot? Did you check before starting on your venture?

  • roam Level 6 Level 6 (13,560 points)

    My suggestion to clone from safemode was to get a working version of disk utility to try and repair your HD which is now replaced. Safemode shouldn't  be necessary anymore.


    With a new HD installed, can you boot into the 10.6 install DVD? If so reinstall a fresh copy of the 10.6 OS onto the new HD.

  • roam Level 6 Level 6 (13,560 points)

    The new drive is completely visible and functional

    In Disk Utility does the new Macintosh HD say Mac OS Extended (Journalled)

    Does the Seagate drive itself say Partition Map scheme: GUID  partition table ?


    The second parameter is also necessary so check that please.

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