Glad to hear that its working now. Since you booted with failsafe, I'm not sure if this suggestion will work, but you could try looking at the contents of dmesg to see if there are any problems/error messages. That might give you a clue as to what the issue was.

dmesg |more

or

dmesg > dmesg.txt - to have the output of dmesg placed in a text file in your home directory.