I just bought two graphics cards from a guy and a power supply.(I only used one graphics card and both wouldn't work.) I went home took out the old power supply and the old graphics card, put in the new graphics card and wired up the new power supply and now it beeps 6 times on boot up and then nothing just black screen. i wired it up just as it was with my old power supply. I booted up the computer with no graphics card and it booted normally but didn't show anything. I also tried taking out the ram then starting up the computer then putting it back it and starting it up and that didn't work. These graphics cards look to be in great shape almost no dust I don't want to think they are dead. I'm not to sure what my motherboard it but it does have HP on it my computer is the HP Evny. So I'm not sure what to do. Help please 
