MOST IMPORTANT if you are concerned or feel that you do not have skill to fault find on electrical equipment then seek help from someone who knows. 3 steps to check; first is there mains voltage at the 240v AC side of the charger, check the mains supply fuse, the supply switch is on, if ok check if mains is getting to the charger by using multimeter. two if mains is at the charger switch on and check the output with the multimeter should be 13 - 14v DC. (some chargers have a output fuse - check) if ok check at the batt for 13-14v DC. if all these 3 steps are ok then the charger should work.