I've not been able to startup my MacBook Pro. I made a backup of Mountain Lion using Lion DiskMaker 2.0.2. When I press option and the power button then select the USB drive, the grey screen with the apple logo and spinner appears then shortly after I get a solid royal blue screen. Is there anyway I can boot from the USB drive backup to fix my computer?

  • Sorry I can't answer directly without access to the Mac and some more triage / details, but I'll answer what I know in case it helps.
    – bmike
    Feb 12, 2013 at 16:48

2 Answers 2


Lion Disk Maker is a third-party utility. It’s likely that updates to OS X changed the startup behavior slightly for how your machine operates.

Any reason you wouldn’t use Recovery Disk? (Command + R on boot.)

You can also try booting to the USB drive, but enable verbose mode (before you select the USB drive, hold down Command + V) to see if there are particular errors shown when it is at that blue screen.

Last bit of hope: the author appears receptive to personal technical support questions by e-mail (that’s pretty cool).

  • When I use the recovery disk it shows the blue screen as well. When I use verbose mode for the recovery or the USB backup I'm not seeing any errors. Is there a particular spot where it might say an error?
    – wwwuser
    Feb 12, 2013 at 16:26
  • 1
    @wwwuser Verbose mode won't help, since you are past the portion where verbose mode ends. The blue screen is user boot land - so verbose mode didn't have fatal problems or you would have stopped before getting to the blue screen.
    – bmike
    Feb 12, 2013 at 16:47

This blue screen indicates that the user portion of the login process has started, and is hung.

How exactly did you get the InstallESD / Mountain Lion installer? What exact hardware downloaded the installer and is that the same hardware as you are trying to boot? If so, then you can conclude that either the copy process failed or drive / hardware is faulty.

If not, you might have a perfectly working USB to run an installer - for the hardware that downloaded the initial package but not the hardware you are now trying to install from this package.

It's not really an answer, but Apple hopes that everyone will avoid this tracking of InstallESD versions and hardware dependency by using a Recovery HD on each drive. That would be the ideal way to re-install your OS since it's more closely tied to the hardware and less likely to run into conflicts unless you take a HD from one Mac and move it to another.

  • I downloaded Mountain Lion from the App Store and placed it on a formatted USB drive using Lion Discmaker. My MBP has the latest version of Mountain Lion on it. I've tried booting from the recovery drive, but the same royal blue screen appears.
    – wwwuser
    Feb 12, 2013 at 17:21
  • Bummer - if the Mac can't boot to it's own internal recovery HD, then it might be hardware even though the vast majority of times you get a blue screen it's software. You seem to be doing everything correct keeping the download from the Mac and putting it on USB, so unless the maker of that tool can support you, I'm out of ideas. Hopefully someone else here might have a better clue at this point.
    – bmike
    Feb 12, 2013 at 19:11

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