Troubleshooting Airmar DT800


I’m in the process of building boat for mapping lakes, but I’ve run in to some problems. The sonar (Airmar DT800, without the speed monitoring) used to work but now it have stopped working. So I’m trying to figure out why…

The sonar setup is done following this instruction: and it was working on v1 of my boat. I’m currently on v2 with the hull using mostly the same hardware setup. Just the ESC and motors that have changed.

I wonder if I can take the sonar and plug it in to the computer and see if that is the problem, but I don’t know how or what I need to do that.
I do have some extra 485/TTL-converters that I’ve tried without success so I don’t think they are the problem.

I also have an Arduino UNO and some at home that I tried to hook up, but as soon as I try reading about how to use these things and how they work my mind goes blank and I can’t understand anything.

I know it is much to ask, but I think a need a full blown picturebook to understand how to succeed with this. At least that’s how I feel right now…

Any help would be appreciated.