My Humminbird 717 approx 4 years old no longer turns on.I have checked the fuse and the slide-on base is getting 12 volts.No corrosion.This is the 3rd item from the importer to die.First was the Minn kota batt charger then my Minn Kota Riptide bow mount so I know the there address for repairs!! Any ideas ? Thanks.