Samsung UN46ES7500F E-Manual page 482

You can also have loud humming if the back
of your Plasma TV is too close to a wall or
other hard surface. Also, try rerouting your
connection cables.
An improperly installed wall mount can also
create excessive noise.
Image Retention (Burn In) Issue.
To minimize the possibility of
for PDP TV
screen burn, this unit is equipped with Pixel
Shift screen burn reduction technology.
Pixel Shift lets you set the picture so it moves
slightly up and down (Vertical Line) and side
to side (Horizontal Dot). The regular, slight
movement of the picture reduces screen