Dual G5 Problems

After waiting all this time to finally get my G5, it been having problems since day 1. I am very unhappy. What happens is when the computer is off and I then turn it on the screen stays completly blank. I think it is still booting since I can boot it into target disk mode and when i tell it to boot from cd i can hear the cd spinning. I normally have it hooked up to a 20" studio display, but since i have been having these problems I also connected a monitor to the dvi port. Neither of these display anything. When i first got it and it had this problem, it went away after a couple restarts, but I guess the actual problem didn't go away. I have already tried reinstalling the video card (9600). Has anyone ever heard of this problem and if it is fixable? I really don't want to give it up right after I got it (last week).