Signal keeps cutting out
First off, check your lead by holding one end while plugged into your amp (turn your volume down). If the break still occurs when you give the cable a waggle, then you have a dead wire.
If not, the problem is in your guitar. Check that the jack- socket nut is tight and holding it in place: if not, tighten it up with pliers or a spanner. CruzTools makes the brilliant Guitar Jack And Pot tool, which will fit every fixing on your guitar.
Next, you need to look at the actual jack itself. Assuming your wiring is sound, the problem most likely lies in the terminals. The sprung steel can bend out of position over time, but it needs to be in contact with the tip and barrel of your cable for your signal to work. Plug the lead in and gently bend it back into position, so you get a tight fit when plugging in.