You would prob need to take it to a shop. It requires full disassemble down to system board. Remove system board and locate the dc-jack. (where you plug in the charger)
on the other side of board (the bottom of jack there will be 4-6 legs that hold it in place. You will need a multimeter of some sorts that reads volts and check the rear leg and center leg for 19volts. Occasionally its another leg but just check them all. Sometimes the legs just need to be touched up with solder, and other times you have to replace the whole jack.