A low-noise block downconverter (LNB) is the receiving device mounted on satellite dishes used for satellite TV reception, which collects the radio waves from the dish and converts them to a signal which is sent through a cable to the receiver inside your home or office Signs of a faulty LNB include missing satellite television channels, video pixelation, signal drop-out during heavy rain or the complete loss of signal If you plan on changing the LNB - please note the exact angle of the faulty unit before you remove it and replace and turn to the same angle for the best signal reception. And insulate the join well to avoid future moisture damage There are many factors that have an effect on satellite signal but this unit is a good and fairly cheap starting point if you would like to DIY