Ok so, I was playing an online game on my HP Pavillion 6500 when suddenly a purple screen with pixilated squares appears. I reboot the laptop and now when it's starting up all I see is strange pixilated screens (usually black, with squares) similar to TV static. It does not respond to any input and doesn't get to the windows logon screen. I have tried connecting the laptop to a external monitor, but it seems that the laptop doesn't recognise it. I'm just wondering what hardware part has died and what the problem might be?