I recently received a new in box meridian marine gpsr as a gift ,,unknown to me or the giver of gift that this unit has been discontinued since 2004 ,,the factory was no help as it is out of warrenty ,,any help on how to power up this unit for the first time would help,,,yes I know were the power button is + what direction the batteries go in + how to close + latch battery cover --so no stupid comments ..does this unit need the sd card to turn on?? help--