Hello, Your result on the monitor is like a television without a connected antenna, right? I had the same problem on my Llano system. This problem was months ago, but if i remember right, the firmware for the Radeon is missing. Please install the debian package "firmware-linux-nonfree". You can find this package in the non-free section. I'm not an expert, but hopefully, it helps to solve your problem. Best regards Bernhard