I have a Gateway 550GR desktop that I purchased in August 2004. This weekend all of a sudden the monitor stopped receiving a signal from the PC. The monitor has power and all I get is the screen telling me there is no signal. I have checked all the connections and they are fine. This particular computer has two monitor ports in the PC. One has the video card and the other doesn't. I obviously have the monitor plugged into the port with the video card. Unplugging it from the port with the video card and plugging it into the one without isn't working. I couldn't remember if I had to go through my Control Panel to switch the monitor port or not. It's been too long. I have also replaced the power supply in this computer about a year and a half ago and it has worked every since until now. Is there a way for me to trouble shoot the problem? I can hold in the power button on the tower and turn off the PC and when I push the button again, it always reboots, but I never get a signal. Is it the video card? The RAM? The motherboard? Please help.