charging malfunction with tomtom go720?

My tomtom will not take a charge unless the cord is in the perfect position. (wrapped around the mount) it seems as though the spot where the charger is plugged in the back of tomtom is malfunctioning because when the cord is moved at all the green charging indicator light shuts off. i was going to try to take it apart to see if the power accessory was loose but i dont have the proper hex-head screwdriver. after reading many complaints about tomtom not repairing there products i would like to find some way to do it my self. im fairly certain it isnt the battery itself and i have used 3 different chargers and they all work the same. any ideas?