Hiya, trying to resolve an issue with my homebuilt computer crashing while playing games. I had an HIS Radeon 5770 installed. I removed it and put in a Radeon 6670. When I powered the computer up, I got "no signal" on my display. I removed the new card and put in the old card again. "no signal" I tried both in another PCIe slot. "no signal" For the record, I have a Rampage III Formula mobo. There's no onboard video, so I can't try the computer without a video card. Help?