1) At the top of the board there is a USB port. Look to the left of the USB port (in the same socket) there is a black, two-pin jumper used for changing firmware on the board. This jumper will prevent the board from powering up if it is on both of the pins. For normal function ensure the jumper is resting on ONLY the bottom singular pin.
2) Test the battery with a load tester. Replace if needed.