A snowy picture is usually the result of a poor signal or a TV on the wrong input.
If this is happening on all of your TVs, it's probably a problem with the outside lines and will need to be repaired by a technician. If this is occurring on one TV:
- Ensure the TV is tuned to the correct channel (3 or 4) or on the right input (e.g. HDMI, Component, Video).
- Make sure that all of the cable connections from your wall outlet to the receiver and the receiver to the TV are secure, including any components in between (e.g. sound system). Bypassing some components and checking if the signal improves can also help identify the cause (correct configuration: cable outlet > digital receiver > television).