I have an old MacBook laying around not doing much, so I decided to install Ubuntu 13.04 on it, and dual boot with OSX.
From within OSX, I repartitioned the drive, reserving half of the 250gb HDD for each OSX, and Ubuntu.
I plugged in my bootable USB drive created using UNetBootin, and booted into Ubuntu. I installed the OS, and rebooted my system after removing the USB.
I got to the GRUB menu, and selected Ubuntu... The GRUB menu disappears, and the screen just stays the purple background color of GRUB.
I got to the GRUB menu, and selected OSX, I got the same purple screen, but after a short while I got this.
I replugged my bootable USB and rebooted
After selecting UFI boot, I see
Secure boot not enabled, and then the screen goes black...
What can I do to repair my MacBook? What could be causing it to no longer boot from either HDD or USB?