MacBook Pro can't boot: shows Apple logo then grey screen There is a MacBook Pro from 2012 with Mountain Lion that won't boot. The Apple logo is showing, the spinning wheel and then it just goes to a solid grey screen.


I've tried to hold Cmd+R while booting, this does nothing.
I've tried to hold Shift while booting, this goes to a solid blue screen
I've tried to hold Cmd+Option+R while booting, this does nothing either.


I'd rather not re-install OS X. Do I need to reset the NVRAM?
Try to do a file system check via single user mode.


Reboot and immediately press Cmd+S
Wait for the command line and then type /sbin/fsck -fy
Have a tea. And a cookie.
Have a look in the output. If the HDD is failing you might see something like I/O Error. If you see something like ***** FILE SYSTEM WAS MODIFIED ***** then you can try to do it once more. If Volume X appears to be OK then you might be lucky.
Type reboot and let it boot.


More info on apple's website.

Good luck!