Try this
Antenna connection
If the symptom occurs only on a specific channel, it may be a broadcasting signal issue. In this case, it is advised to have your antenna/cable provider check the problem.
If the symptom occurs uniformly on all channels, you may need to have LG Electronics service technician check it.
Set-top box connection
Sometimes, noise can occur due to the set-top box.
Try turning off the set-top box or removing the connected cable to check if the noise disappears.
If the noise disappears, please contact your set-top service provider to have your set-top box checked.
If the noise persists, try lowering the TV volume to 0. If the issue is still not resolved, it is advised to contact LG Electronics service technician for further troubleshooting support.
This guide was created for all models, so the images or content may be different from your product.