Reason: There will be snow picture and noise when signal wire is loosened or signal is weak (less than 60db).
Solution:
1. Connect the antenna or signal wire again.
2. If only some channels have snow picture and noise, but the other channels are normal, this may be the signal problem.
3. If the local signal is weak you can use a signal amplifier.
4. Please call service when your TV not ok after above operation.