I have a AMD Radeon HD 6850 graphics card which I have hooked my monitor up to via the DVI/HDMI adapter. The graphics are great but I can't get any sound from my monitor's speakers, however I do have sound when I plug in my USB headset or headphones into the headphone jack. I have tried an older version of the Catalyst driver (12.2) and the Realtek driver as well as unplugging my monitor then plugging it back in. Can anyone fix this?