So I just bought a MacBook off of craigslist, and when I went to plug it in, it showed it as being plugged in, and it was pulling power from the magsafe, but it had the message (Not Charging). I have tried rebooting, resetting SMC, and I'm getting really worried. Do I need to replace the battery, or is this a magsafe issue? Or is this a problem with the port? Thank you to anybody who helps.