Lowrance chart plotter misbehaving

[Fascadale]

Arrived at the boat today, first time this year

Switched on the electrics, turned on the rather ancient Lowrance Globalmap 3500c. ( the back up back up chart plotter) only to be greeted by the message “GPS Module Not Responding”.................it was working fine last season

Is there a simple and cheap fix for this or should this somewhat antique bit of kit be disposed of.......I do have two more modern systems on the boat

 

[black mercury]

Mine was the same. Check connections to antenna, make sure they are clean. After couple of hours of chartplotter being left on, it cured itself. Has been fine since.

 

[bromleybysea]

The cable that came with mine has a in-line connector just before it enters the antenna. This sometimes needs pulling apart and cleaning. The Globalmap 3500c was a good, reliable bit of kit in its time. I keep mine as a backup and as a data source for a PC-based chart plotter. I also have an even more ancient Garmin GPS, for which I have just replaced the GPS module for the second time, so they do fail. As an interim measure I had a cheap antenna from fleabay plugged into it and tucked under the headlining above. Worked fine.

 

[Rocksteadee]

It could be that having been left for a while it’s onboard almanacs is out of date, which tells it where the satellites are. May need a couple of hours to refresh itself.
there should be a page showing what satellites it can see