Unplug the charger from the system and plug it into the wall only. Does the LED on the charger or end of the cable come on? If not, the charger is faulty and will need to be replaced.
If the charger LED comes on, and goes off when you connect it to the system, either the power jack or board is faulty, or the system board is faulty. Where you go from here depends on the system model. Post that and someone can assist you.
