Hi, sorry that may be late to this post. What may have happened, when you dropped your laptop, is that the CMOS battery may have been knocked from its placement. Or the main battery plug to the motherboard has become detached. The battery is inside of the laptop. To reach it you have to remove the 10 small screws on the bottom of laptop. After removal of the protection plate you will notice that the main battery is to the right of the motherboard and the CMOS battery will be the small round silver battery to the left. The plug to the main battery is black which sits to the left side of the battery. Press the plug careful not to apply to much pressure. If you hear a slight click then that was the source of your problem. The CMOS battery is pretty simple, carefully remove the battery, and reinstall it.