LG 42PA4500 Owner's Manual page 233

Sound problem
❐
SETTINGS ➾
Try Sound Test to verify that sound signal output is normal.
When the test sound is normal, check connected external devices or broadcast
signal.
ꕢ Screen display is on but no sound.
• Check other TV channels.
• [Depending on model] Make sure the
Customer Support ➙ Sound Test
TV Speaker is set to On.