So I got this nvidia quadro 600 gpu to put in my dell optiplex 745. I plugged it in (changed the bios to accept the card before hand) and no signal to the monitor. The gpu's fans start up, and the motherboard beeps (because the motherboard keeps detecting a fault in the system it doesn't have, but it lets me know its working. This fault dosent concern the gpu). I've already tried rebooting everything, repluging everything, dusting everything and nothing. Need help please.