You may have fixed it already, but try holding in the power button for about 30 seconds, system should turn off. Turn it back on again and see if it works normally after that. If it does not power off with the power button, unplug it from wall power and remove the battery, hold in the power button for about 30 seconds, plug in the laptop to wall power and see if it turns on. If not, plug both the battery and wall power back in and see if that works.