AMD Motherboard - No Video. Doesn't Work?

I have MSI K9N Platinum Socket AM2 NVIDIA nForce 570 SLI MCP motherboard. Recently I was having problems with one of my HDs freezing during transfer, so I RMAd the HD. Then I saw the same problem with another HD. After switching cables, the problem seemed to go away, but then I restarted the computer and got no video output on the monitor. I restarted again, and this time did get video output. Then I restarted again just to make sure, and since then have been unable to get video output. Anyway, called customer support and RMAd my EN8500GT video card. Now I just brought over friend's video card and same problem!!!! I have no picture. I have already tried removing one of the RAM card, using different PCI slot for the video card, etc, but nothing has worked. The monitor does not turn on (the monitor is working when I hook it up to another computer).

I am at loss here and somewhat upset because I might have RMAd two items whereas the problem was with my motherboard. What do you guys think is the problem? Could the motherboard really not be able to produce a picture?? Everything in my computer turns on and runs fine - fans are on, video card is on, etc. It just that I can't get a damn picture on the monitor. I would really appreciate any input.