Adrian Caspersz wrote:

Two tests.

Try HDMI from another source. If same fault here, blame Samsung and call
their support. Or maybe cabling interference issues.

Or temporarily try another OS on your hardware. A linux live CD would do.

If it doesn't occur on the other OS, then grab the video timing info
from that, and compare with your current OS.

xvidtune -show


Thanks for responding. Hum seems to have been the problem since
re-routing the hdmi cable fixed it.