OK, my computer has been fine until now. When I start my computer, the normal booting screen doesn't show. My monitor just continually flashes "SELF TEST-CHECK YOUR PC AND SIGNAL CABLE-MONITOR IS WORKING". My graphics card is an ATI Radeon X1650 which replaced an nVidia GeForce 4 MX 440. I have inspected the computer but I'm not sure of the problem. Help?