Sometimes, coaxial aerial leads can become corroded over time due to water penetration, which in turn may cause interference to your TV signal. This is commonly known as ‘water ingress’.
Below is the BBC’s step-by-step guide to checking for water ingress:
1) Unplug the coaxial cable from any outlets or ports into which it is connected.
2) Remove the connectors from the ends of the coaxial cable. This is the most likely place for moisture to build up.
3) Examine the tip of the cable, where you just removed the connector, for signs of water damage, such as corrosion.
4) Look at the entire length of cable for any signs of weakening along the insulated outer layer. Search for cracks or tears to the insulation where moisture may have seeped through to the copper conductor.
5) Once a cable has water damage, it can no longer carry the signal effectively and should be removed.
6) Consult a reliable aerial contractor and have it replaced.
You should always contact a professional aerial installer to check cables where connections are not easily accessible (e.g. on a rooftop)