You can quickly banish a grainy or snowy picture on your LCD TV by first knowing few of the most common causes. For example, if you recently switched to a new cable or satellite TV provider, the setup configuration could be incorrect. Bad weather can also bring TV reception problems. Thunderstorms in the area where the station is broadcasting can produce unclear pictures. Magnetic interference can come from both outside and inside sources, too. Tackle these issues one at a time to help you bring your TV picture back into clearer focus.
Turn the channel to determine if the graininess is an isolated problem. If the issue does not appear on other channels, the problem is not likely in your set. Contact your cable or satellite TV provider. If the the unclear picture is displayed on additional channels, go to the next step.
Tighten all cable cords and external connections that go directly to the TV. Loose attachments will cause a weak picture or no picture at all.
Raise the temperature in the room. Many LCD TVs operate best in temperatures ranging between 5 to 40 degrees Celsius, or 41 to 104 degrees Fahrenheit.
Move the TV away from appliances that produce cold air or noise. Vacuum cleaners, blenders and humidifiers when operating, may cause TV interference.
Look for visible damage and loose connections on the outside antenna and cable lines. Do this from a distance without touching any of those parts. If damage is found, contact a service technician for further inspection and repair.
Reset your LCD TV. Turn it off, then unplug the cable box, if you use one, and any other external equipment from the AC outlet. Wait two minutes, then replug.