Anyone have an issue with interlink where whichever unit you plug into position #1 it doesn't pick up the gps. Whereas either one in position #2 works. I have 3 units two 788c's and one 997si. I can plug any combo of the three to the interlink and only get the one in #2 to connect to the Gps.
Thanks for any suggestions!

1) Are you moving the cable from port 1 to port 2, or trying another unit on the same cable?

If you using the same cable then the problem would likely lie within the cable(s) running from the unit base to the port 1 connection on the unit.

If you are moving the cable from port 1 and trying it in port 2 slot then the cable should be fine.

2) Please restore defaults on both (all) units and verify that both (all) have the lastest available update.
997c SI is 5.840
788c is 5.420

3) Export All Nav data from each unit to an SD Card for back up then delete all nav data from each unit.
How to export nav data on units with waypoint management:
Menu twice and right cursor to the Nav Menu
Cursor down to Waypoints, routes, Tracks then right cusor
Select Options > Select All > Export and data will be
sent to the blank SD card.

4) After Exporting all Nav data take your sd card and load your waypoints into Humminbird PC. Look for any waypoints with symbols such as ? # ( ) etc in the name. Rename any waypoints with symbols in them. Be aware waypoints are also limited to 11 characters including spaces.

5) Delete all Nav data from you unit. Menu twice and right cursor to the Nav Menu
Cursor down to Waypoints, routes, Tracks then right cusor
Select Options > Select All >Delete

6) Reset the interlink following the instructions at the below link:
http://www.humminbird.com/FAQ.aspx?ContentId=3079

7) Clear buffers on the interlink follow the below link:

http://www.humminbird.com/FAQ.aspx?ContentId=3080

8) Then reload your edited waypoints back into your primary unit.
Make sure the unit is synced with the interlink.

If you still are having problems with the interlink then we may need to take a look at the interlink box here at the factory along with your interlink cables.

Thank you

Deborah @ Humminbird

Thanks for the indepth reply!!! I should let you know that I am not using the same cable. I am using 3 cables that go to all 3 units. Also I just bought a new interlink box thinking for sure the older one was bad but I get the same results. As far as the updates they were current as of 8/1/11. I found out today that there is a newer one as of late August 5.840. I thought it was a good update for both units. I will update them this evening and go from there. Thanks!!!

Are you trying to hook all three units up to interlink and share the data between all three units?

No, Not trying to get all 3 units to work at the same time. Interlink will only support 2 but I am trying to get a combination of two to work on the same interlink box. I have the 997 mounted on the boat near the console and the 788 in the console but the 788 no longer will read the depth since trip before last 3 weeks ago. I have just been using the 997 but the 788 was the one plugged into the interlink sharing the gps with the one on the front but I kept getting interlink disconnect and losing the gps on both 788's since last April. Since then, I would just get under the console and unplug the cable from the interlink and plug directly into the gps cable depending on which I wanted to have the gps(front or console 788) I thought a new interlink box would fix this but it didn't. With the new box the interlink stays connected but I only get the gps on the one plugged into #2.