Hello, I'm new to boating. In the process of buying a 97 larson. I took it out this weekend and it ran really well but with anything old there are a few issues. My first issue is the depth finder, it didn't work. I pulled the fuse and it appeared good. Can someone give me a little direction on what I should be looking at and where to go with it? When I say it didn't work I mean it didn't light up like it didn't have power THANKS!