Question : Problem: PowerMac G4 won't startup

I have a PowerMac G4 IGHz dual FireWire box that won't boot into the OS.  The HD spins up, but I don't get the Apple tone or any image on my display. I tried reseating the RAM and video card, but no change.  Any other ideas on where to troubleshoot?

Answer : Problem: PowerMac G4 won't startup

When I installed my new aiport card I had a similar problem.  After talking with about the prob., it was solved by restarting and holding c with the installation disc in the drive.