Model A1502 / 2.4, 2.6, or 2.8 GHz dual-core Intel processor / Released October 2013

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no entry sign on OS reinstall

Did a reinstall from internet of mountain Lion and now get no entry sign...


Btw, the disc appears fine, in target mode it can be booted from by another computer...

Answered! View the answer I have this problem too

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Did you enable a firmware password? What do you see: A blinking question mark or a do not enter symbol?


Its a do not enter sympbol


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2 Answers

Chosen Solution

Do you have access to a second mac which has a Thunderbolt connection and a Thunderbolt cable?

I think you'll need to scratch the drive and re-install the OS. By leveraging the second Mac we can setup your system like a HD to it using Target Disk Mode.

The other option here is to setup a USB thumb drive as a bootable drive using the other Mac system and installing on it the OS installer. Here's the steps for that:

  • Get a USB thumb drive (16GB or larger)
  • Download the OS installer from the App Store, make a backup copy
  • Then create the GUID partition map on the thumb drive and format the partition with Mac OS Extended (Journaled) with Disk Utility.
  • Run the OS installer and install the OS onto the thumb drive.
  • Once done, copy to it the copy of the OS installer.
  • Restart your system holding down the Option key so you gain access to the boot manager select the thumb drive.
  • At this point you should be able to reformat the drive using Disk Utility on the thumb drive and using the OS installer on the thumb drive install a fresh copy of the OS.

Do make sure you are connected to the internet as there are some updates your system will need.

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Most Helpful Answer

When you see a circle with a slash symbol instead of the Apple logo, it means your Mac couldn't find a valid System Folder to start up from.

Your machine shipped with 10.9 and will not boot from a lessor system.

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No, it's a 2012, and automatically reinstalls OS 10.8 from the internet.

After the install is complete it won't boot.


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