I have a 520C also that I sent back to Lowrance, went through Linda even. Its been 3 weeks to a month and havent heard anything back yet. They said it could take a while because they are low in stock of the 520s. Good luck, I dont NEED mine back anytime soon, but Id be nice 2005 Sabre, 150 XR6, Minn Kota Fortrex with Lowrance electronics