This video tutorial is in the Sports category which will show you how to reset a Mavic Wintech. After you have installed the battery and you notice you have a blank screen, use the reset button inside the computer to reset it. This is not mentioned in the Mavic Wintech operating manual. For this, remove the battery and you will see a little compartment with a little silver button. It looks like a starter, but that is the reset button. Press the button with a sharp object and place the battery. It beeps and the screen comes on. Replace the cap and you may have to re-calibrate it.