Mac Monitor Issues

Hi,

I know that this may not be an "Intel" Mac question, but this is the closest forum that I could find that may help. Here goes:

I have a 400MHz Graphite Mac G4 (don't laugh, it was donated) and I do a lot of video editing. Since I don't have a single large high capacity hard drive, I find myself swapping out my internal drives a lot (a bad habit, I know...).

That may or may not have anything to do with my problem which is: I can't get my monitor up anymore! I start my Mac (and restart it several times) and the monitor just never comes up (the power light stays amber as if it's asleep). Of course, it's plugged into the computer as well as its power source and I'm not getting the "monitor cable disconnected" message on the screen like when it's unplugged from the computer. The monitor works fine with other computers.

I don't get the impression that my CPU is doing much at all when I power up. It sounds like it now has a shorter cycle of activity than it used to. The computer briefly spins up, then idles (all you can hear after that is the fan spinning). The CPU doesn't give me the other clicking and spinning sounds that it usually does as it goes through its routine just before letting me log in. This leads me to believe that it may be a processor or video card issue. Has anyone ever run into this problem or know any fixes (or any inexpensive video cards as a replacement if necessary)? Even a diagnosis of what could be going on would be helpful.

Thanks,
Jabbar