Hi deltapilot,
Strip the system back to basics ala Hal's tip
http://forum.pcmech.com/showthread.p...threadid=12753
Try a different Monitor cable.
Make sure that the AGP card is firmly pushed down into the slot. It sometimes takes quite firm but gentle pressure until it clicks down. There should be very little of the AGP connector metal showing above the AGP slot. Try it again a few times.
Try putting in PCI video card (any one will do). If it boots, go into the Bios and make sure that the AGP card is the Primary Video card and is detected first. This setting is something like "Primary VGA Bios Sequence" or "Primary Display First".
HTH