Samsung PN51E6500EFXZA - Manual (Page 629)

Others (Troubleshooting)
Purple/green rolling horizontal bars and
buzzing noise from the TV speakers with a
Component cable connection.
Remove the left and right audio
connections from the Set-Top box. If
the buzzing stops, this indicates that
the Set-Top box has a grounding issue.
Replace the Component video cables
with an HDMI connection.
The picture won’t display in full screen.