Samsung NP900X4C not accepting charger but runs on battery

I have the same problem. Should the motherboard be replaced?

Joe... Before answering with the easy answer, read the original question and see how this test has been already performed and charger functioned confirmed and ruled out. I've had this problem and Samsung had to replace the motherboard. It is happening again with the new mobo but when I disconnect the power and reconnect with the unit switched off, it starts charging again. Its a know problem and you need to get this warranty serviced.