Zach,
I had the exact same problem with a 12″ G2N. I tried everything i could think of and i just gave up and took it back to the dealer i got it from. Before i returned it though i wanted to make sure it wasn’t a power issue i was having on my boat,so i plugged it into their power source and sure enough after 5 min. I turned it off and then back on and it did the exact same thing. All i can say is that the product is defective internally and you should either return it to the dealer or send it back to Humminbird to be replaced. Now im having trouble with my 2D sonar displaying a blank white screen so if anyone knows what to do here then please advise.Power source is good with 12 gauge wire. What really sucks is i like everything humminbird has to offer with their clear view mega si/di its just a little annoying that i have purchased two different units that both have had issues. Thanks and good luck Zach.