Blank screen with ati radeon sapphire 3850 hd (agp) card

I recently bought a ati radeon sapphire 3850 hd (agp) card now i know i installed it right and connected the wires where they need to be but everytime i plug the DVI-I cable in when i start the computer up i don't get anything (black screen) but i hear it running and the computer lights r on and the card's fan is working properly. If you have a solution to my problem please e-mail me XxMurdokxX@yahoo.com

thanks and i appreciate it ^^

Yes. Here's the thing, I had to use the DVI-I adapter that came with it in order to at least plug it in, but cause it didn't have just a regular VGA cable like the one card I have in now (NVIDIA GE-FORCE 7300 GT) The funny thing is that, when i reinstalled the GT I used the adapter from the Sapphire and used it to plug it in (GT had a VGA and DVI-I port) and didn't have any trouble starting up or anything. So I guess i might have a defective card.