likely one of two things.
1) A damage component cable port. (pins inside or behind the port are likey damaged, and it needs to be replaced.) This repair needs to be done by ones self, as the labor is more expensive than buying the system.
2) your GPU oveheated, and the board needs to be replaced. replacing the board is similar in cost to buying a new device.
these items are cheap. 40-80$ depending on where and when. so i would just look at replacing at your local game store.