LG 47LM9600 Owner's Manual page 194

Pictures
HOME Settings
Check if the image signal output is normal by beginning with Picture Test.
If there is no problem with the test image, check external device connections or
broadcast signals.
Problem
Images from previous
channel or other channels
linger or the screen shows
annoying lines.
SUPPORT Picture Test
Try adjusting the antenna to the direction of the TV
station or refer to the manual for proper way to connect
the antenna.
Solution