I just recently bought a 1.5 ghz 15 inch powerbook off craigslist, which im extremely pleased with. But for some reason when i plug the laptop in with the charger the battery is not charging. when i look at the battery icon on the top, it shows that it is plugged in with that icon, but when i click the icon it says the battery is not charging. I cant find an option to fix this. Can anyone help me?