rMBP Late 2012 keeps turning off

[3lite]

If I leave it unattended for say 3+ hours, inevitably when I come back it automatically shuts itself off and I have to hold down on the power button repeatedly to turn it back on.

What do?

 

[Freyqq]

Seems to be crashing upon going to sleep. Try an SMC reset: http://support.apple.com/en-us/HT201295.

If that doesn't fix the problem, do a repair install of OSX.