System shuts down during gameplay won't turn on for hours.

Recently my PS3 would run a game normally and while playing the system would shut off completely there is no blinking lights nor is the red standby light on. I can unplug it and it won't come back on and the light may come back on after a few hours. The time when the system shuts off is intermittent but once it does it stays Down for hours as if it was unplugged all together.