No video at POST

Ive just built new system, using an ECS P965T-A Ver 1.0. When i try and POST the screen stays black and the monitor never switches on, the light on the monitor stays amber.
I installed a PCI graphics card and managhed to get into the bios and change it so it used PCIEX graphics cards first. Howeverit still wouldnt work when i remvoed the PCI card, i have only had the Galaxy 7600GT for a month, yet my one year old ATI X300 Boots up perfectly, i Mad sure i had plugged in all the pwoer connectors properly, and i even used the 4 pin molex por on the motherboard, which is for stability, just in case. PSU is a Thermaltake butterfly 450W so thats fine. Intel 805 - brandnew.
Please someone tell me there is a logical thing im not doing.
Cheers
Matt

Not sure about your board - does it have on-board GFX?

Anyway, try clearing CMOS - this should revert everything back to normal - if the board does not have on-board, then PCI-E should be the first option that is used. If it does, then on-board should be first. Either way, you should be able to get into BIOS.