Raymarine A57d 57" Fishfinder Chartplotter Combo US Charts Preloaded "l365" Questions

Raymarine L365 Fishfinder not registering data, it just flashes I have a Raymarine L365 Fishfinder and it is not registering depth, temperature. It just flashes on the screen. Any suggestions? Got a ...

...plug is square to the back when you insert it, and lined up with the notch at the top. I have the L365 head , lost to someone that touht he needed more than me.my phone is (616) 821-0607. The head ...