There is very little that can go wrong with an aerial socket other than the connections to it. So take it off the wall and check that both connections are OK. Next check the other end. If you have multiple aerial outlets and just one aerial, then you should have a distribution amplifier. That is where you will find the other end of the cable.
If you don't have a distribution amplifier then you need to get one because Digital TVs (Freeview) need more signal than the old analogue sets.
T
August 2010