Plug-in your GPS and press the reset button on the bottom of your GPS. Make sure your power adapter is plugged in fully to the USB charging port and your cigarette lighter socket (12-24V DC accessory socket).
Make sure your SD Card is inserted correctly.
If this does not work, try using a different power source to charge the battery.
Plug the GPS in and let it charge for at least an hour before pressing the reset button on the bottom of your GPS and turning it on.
If the GPS still does not work after trying these procedures, return the GPS to Best Buy to have it tested.