LG 47LM9600 Owner's Manual page 195

Problem
Vibrating horizontal/vertical
lines and fishnet patterns
appear momentarily.
The screen display freezes
or does not work properly in
digital broadcast.
Digital broadcast is not on
even though the cable is
connected.
Such a problem may happen when there is strong
electronic interference. Turn off other electronic devices
such as mobile phones, power tools and other small
electrical appliances.
It may happen when the signals are weak or the
reception unstable. Adjust the antenna's orientation or
cable connections.
If the signal strength or quality is low on
call the TV station or administration office for checkup.
Check with cable operator regarding the subscription
and/or signal. (Depending on the subscription, digital
broadcasting may not be supported.)
Solution
Manual Tuning,