I recently purchased a used humminbird from a guy in port alberni. After playing with the fuses it worked great, for 5 minutes!!! We had it hooked up to the engine as the power source and when we sped up the fuse blew. NO problem i thought as i went and purchased some fuses and a hundred dollar battery so this wouldnt happen again but unfortunatly the fishfinder wont work anymore. I turn it on and it makes the noise and the little light comes on but nothing shows at all on the screen. I have no clue how to fix this and im 14 so i cant purchase another fishfinder soon because i spent all my money. I hope to be able to fix it any help would be appreciated.