Ok i bought a ATI RADEON HD 4870. Has to DVI PORTS on it. when i plug it in the fans spins on the Card and Makes Loud Noises. but when i Plug IN the DVI cable to card and VGA to Monitor No Signal? i have the asus m4a88t-m Motherboard but when i remove the Card and use my onboard graphics i get a signal.. i went into Bios and disabled onboard graphics and disabled it device manager so what could be the problem?