Three things you need to try sapi.

First, try a different monitor that you know is working.

Second, swap out a different video card that you know is working.

Third, try both the good video card and monitor together. If you still have problems, try to re-flash your mobo bios. If that STILL doesn't work, then just give up because you're extra ed at that point.

Your symptoms sound very close to what happened to me in the past when I had an older CRT bite the dust, so my guess would be your monitor is going bad.