I recently purchased the above card, and I cannot seem to get the audio to work.
I currently have things set up with a DVI OUT > DVI-HDMI CONVERTER > HDMI IN TV.
Apparently the 280X can do audio through DVI, with the included converter however I can't get it to send any audio. I have tried enabling and disabling different playback devices but it won't let me activate any digital display audio devices (AMD High Definition Audio Device). It says that they are not plugged in.
When I unplug and put it back in a message pops up about an HDMI to DVI connector and needing a separate sound cable.
I have uninstalled and reinstalled all graphics drivers and restarted the computer many times, I have also used other cables and ports.