Computer Down: Board or Video?

[SanSooTiger]

Hi. My computer's monitor shows "Check Signal Cable", so I replaced the video card, but is still doing the same. Now before I go out and get a new board, does anyone think this is a good or bad idea?...

This is what happens when I power on the computer. The indicator light powers on, the CPU fan blows, all other fans blow as well, I'm not certain how to tell if the hard drive works, but that's irrelevant - right? Anyway, by process of elimination, it seems the motherboard must working since the CPU fan is blowing, the power supply obviously works since all other fans are functional. Unless the video card I bought was damaged, I can't tell what the problem might be? Any ideas... anyone? Pleeeeeeeeeeeeeeeze...

overwhelmed

 

[SanSooTiger]

By the way the computer is old, in computer years - it is ancient. Built in 2006. In case component specifications are important here they are:

Motherboard: ESC PT800CE-A REV:1.0A - Hyper-Threading Technology - Prescott CPU Support
CPU: INtel Pentium IV
Video: ATI Radeon 9550 AGP 256M

Your sincere comments is much appreciated...