Do you have another PC to try the video card in? With most mainboard the onboard video will auto disable with the presence of a dedicated graphics card. So if you have the PCI-E power plugged in and still get no video I would lean tords a bad card.
I would have to use the same PSU on another tower I have but since I have tried two cards of the same make and both have not been detected then I'm thinking it's not the card.
I noticed that the fan is powered up independent of the PCI-e cable being attached so it must be getting power from the MB.