Well if that's what the post code means you've likely got one of two issues: 1) your video card may be dying, or 2) your PSU may be dying. If you have another card (one with a lower power draw would be best) try booting your system with that a few times to see if the problem repeats. One final possibility is that the slot you're using has a problem. You could try moving your video card to the other slot and see if the problem repeats.