I've recently purchased a boat the has a Lowrance pick and LCx-27 unit. The GPS on the graph doesn't work. I've been told 2 different things:
1. The puck is bad and needs to be replaced.
2. The LCx-27 had a software update that needs to be loaded.

So, how do I test the puck? And where would I find a software update?
This is new to me, so thanks for the help!