I have also had this problem before. Go ahead and shutdown your computer. Then remove your battery from the bottom of your computer. Then hold down your power button for about 15 seconds for the internal charge to drain. After 15 seconds, plug your charger in then boot your computer up. If your computer will not start, then your charger is defective. If it does turn on, then go ahead and shutdown your computer. After shutting it down, put your battery back in and then keep your charger plugged in and then turn on your computer. Your computer should now be charging.