It is important to remember that the Interlink is very similar to a computer network in your home or office.  Your Humminbird units are like PC's on that network.  Networks crash, PC's crash and sometimes one or the other lock up and have to be rebooted. 

Always make sure you have the most recent software downloaded on your unit.   If you have problems loading your software and need to go back to a later version of software, DO NOT go back past version 5.210 or you can create a problem that can only be resolved at the factory.  Before attempting any of the solutions before, may sure you backup your waypoints onto an SD card.  

Below are some potential issues and the solutions to those issues. 

PROBLEM:  Your Interlink is connected to both units but one shows "unconnected" in the Accessory Test View and there is no Interlink option showing under the ACC menu tab. 

SOLUTION:  Reverse the cables on the Interlink.  Move the cable connected to the Unit 1 port to Unit 2 port and move the cable in Unit 2 port to the Unit 1 port. 


PROBLEM:   Your units always say "change has been made outside the network" and it wants to include what it thinks is new NAV Data. 

SOLUTION:  Check the Interlink status screen and note the number of waypoints and routes in the Interlink, Shared (Unit 1 and Unit 2) and Locked (Unit 1 and Unit 2).

You may find that the Interlink and both units show exactly the same number of waypoints and routes.  Or, one may show a different value but you are still being asked to merge the data each time you turn the unit on.    Please take these steps to "reset" the Interlink

PROBLEM:  If you have followed the procedure to RESET the Interlink and you still get messages, there could be phantom or unreal waypoints being shown.  Or if you see zero waypoints on both units and on the Interlink but it still thinks there have been changes outside the network.

SOLUTION:  Reset the waypoint and route buffers in the Interlink and the unit.  This procedure is a little complex but still easy to perform.  Use the Interlink Status screen to check the values.  Note the number of extra waypoints or routes. Usually they are shown under Locked but not always. Add up the additional waypoints and routes that are shown to be used in the steps that follow.