I am having similar trouble but mine started when I attempted to upgrade the software to the LGC 2000 and my LMS 332c. Since the upgrade attempt my unit is getting the typical “GPS Module Not Responding”. I have read everything I can find and discussed with Lowrance support but they continue to tell its a physical issue with the LGC 2000 and want me to send it back in. Everything was working perfectly before I attempted the upgrade so suspect it more of a software glitch. I did get an error messaged when I installed the LGC 2000 software first but against better judgment went ahead and tried to load the LMS 332 upgrade which installed fine. Since that point it no longer recognizes the GPS antenna I’m afraid that the unit is on the newer software but the LGC 2000 never got the got the required upgrade. The websites warns of this but offers no solution.

I would like to downgrade my LMS 332 software back to the original version if possible as well. Anyone know a link on the web that I can download it from? The Lowrance site only has the newer version.

Thanks!