I have to move a boat that has the Star Log and Depth Instrument installed. It will power on and it is connected to the transducer, but it does not show any data next to the labels that appear on the screen. I looked on the internet and the unit is now called a Silva Star Log and Depth Instrument. I do not know if ComNav Marine joined Silva or Nexus Marine or what, but I cannot find a manual in English under any of these companies that shows installation, operation and trouble shooting information. I would appreciate any help on this.