I have a MacBook Pro with Retina display, when starting up, I see the Apple logo, the bar underneath fills about 1/4 of the way, and then the screen goes black, the mouse cursor is still visible.
Boots to black in OS X mode (I believe 10.10.2? tough to check right now). I can boot into Windows 8 using Boot Camp without incident. I have booted to Disk Utility and run Disk and Permissions Repair. I have booted into Diagnostics, and no issues were found (ADP000 was the Reference Code given). I reset the PRAM, which gave a louder chime than I had been getting when failing to start up OS X, but otherwise no change. Feeling that my options were exhausted, I attempted to restore from Time Capsule, and it won't connect to Time Capsule, despite Time Capsule being the active router whose network I am connected to. Please advise.
(This is my girlfriend's computer, she tells me that she selected an option to perform an automatic update later, that night.)
MacBook Pro with Retina display, OS X Yosemite (10.10.2), null