Hi,
I had an issue once before and was happy with the support I got on the forums.  I am having a problem that I think should be easy to fix, but I am not sure what to do.  I use to have a an 1198CSI at my console linked to a 898CSI at my trolling motor.  Both units had separate transducers and gps receivers.  I now installed another 898CSI by my trolling motor and linked all 3 units with a 5 port ethernet switch.  The 2 original units are working, but the unit I just installed was stuck in demonstration mode.  I think it said no transducer detected.  I got it out of demonstration mode, but I can't use the sonar or map.  I did not install a transducer or gps receiver for the new unit.  I figured I would be able to plug it in and use information from one of the 2 transducers I have installed or I thought I would be able to use the map from one of the other unit gps receivers.  I'm sure it is just a simple settings change, but I do not know what settings to change.  I played around with the settings for a while, but did not make any progress.  
Thank you!