My Son for some reason changed the monitor connected to his AMD Athlon Desktop Computer but the green light on the Monitor only flashes but shows no video. He changed the monitor back to the old one and still could not get the Computer to communicate with the Computer. So far he has tried with 3 different Monitors and still cannot have the Monitor to show any video. Meanwhile, only the keyboard lock or reset button seems to produce any reaction from the Computer. It produces some squeaky sound. The last time I let the Computer sit for a while and tried to restart it with Ctrl-Alt-Del combo, the only reaction I obtained was the orange light on the CD Drive door showing.