In most settings satellite TV dishes operate for many years without problems. Apart from physical damage, the only component of the satellite dish that could become defective is the LNB, or "eyes" on the end of the dish arm. LNB stands for low noise block converter. This device eliminates signal distortion, or noise, and converts it to the signal recognisable by the satellite receiver.
The LNB is a sealed unit. If water or moisture is able to condense on the inside of the LNB plastic cover, the water can interfere with the operation of the LNB.
The LNB rests at the focal point of the dish's parabolic reflector. The LNB receives the digital signal from the satellite and sends it to a perfectly positioned focal point. If the LNB becomes loose or is able to move about on the end of the satellite dish, it will no longer remain in the focal point and will not properly process digital satellite signal.
Occasionally a manufacturer's defect will lead to premature LNB failure in extreme weather conditions. For example, DirecTV HD KAKU LNBs have been known to fail after prolonged exposure to subfreezing temperatures. In the event of a severe ice storm, the satellite dish LNB can become covered with ice. The ice build-up physically blocks the digital signal from being properly decoded by the LNB. In this case the ice must be carefully removed, and then the LNB will function properly again.