Hello, I'm upgrading from an hd6970 to an rx470. I uninstalled the 6970, drivers too, powered off, replaced the cards, plugged the power into the card. When I go to do a first boot, the system never seems to post. Nothing happens, the card doesn't seem to be detected. I know it's in and has power. If I start it up without the extra power, the fan on the card moves.
My system is running Windows 7-64 bit, 8GB of RAM, bios, etc...are all upgraded.
For now I've just put the old card back in.