I just replaced my motherboard 'cause the one I bought was bad...I have tried EVERYTHING but I still cant get either of my PowerColor HD 5770's to display a screen - "no signal" message come up every time. I had my local computer shop test them and they got them to POST but only on one of the two DVI ports (on one card it was the top port, on the other, the bottom) Any ideas on what might be going on here?
I will try to help you; but you didn't give much information about your current system. Also what is your experience level? Going to need to know the exact Make & Model of your motherboard, how much and type of memory you have, and the CPU, PSU, and the version of Windows you are using for starters. Then I'll go from there.