iMac 17 inch intel does not boot - Solid Light, black monitor My coworker was using her iMac and it spontaneously rebooted. As it was rebooting the screen suddently went multicolored with various lines and gradients of Red Blue and Green. Obviously not good so she shut it off. Machine did turn back on but stayed on apple logo for a few minutes nothing happened. We rebooted again. This time Solid Light on power light and Black screen. I removed the ram installed and tried each ram stick on its own and nothing. I also tried hooking up an external monitor and nothing. Any ideas?