Garmin echomap Problem

I am having my normal pre-tournament breakdowns with the Mercury National Walleye Tourney this weekend. Maybe one of you can help. When I turn on my Garmin echomap sv all I get is a box that says Transfer Failed. The first time I unhooked wires and reattached and then it worked. Today couldn’t get to work. Any ideas would be much appreciated. I will take to where I bought the unit but thought maybe some IDO member had same problem. Thanks

Is there a micro sd card in it? Try powering it up with the card out…