This sure sounds like either a power issue like you don't have the power from the power supply to run the card or the card for some reason just isn't getting enough power. The only other times I have seen those kind of symptoms is when you actually have hardware failure like a chip damaged from overclocking/overheating.
Try another cable it may be as simple as that.
If you have another system available that meets the specifications for the new card, try it in there. If not and bought it retail maybe exchange it.
Make sure you have the latest bios for your motherboard too. I know it sound silly but it does the trick sometimes.
If none of that gets you anywhere I'd open a support ticket with who made the card.