When I press the power button, absolutely nothing happens. No lights, no sounds, no display. The adaptor lights up, but once I plug it into the laptop, it goes out. I've tried removing and re-inserting the battery, which should be charged up, but nothing happens. Does anyone know if this could be a hardware or power supply problem or something else? My warranty has expired, but I'd rather not have to take it to a repair shop. Any help would be very much appreciated!