Need a GPS Receiver for an NS25 Humminbird

[freelancer]

So my older NS25 Humminbird GPS Combo is giving me a message on the screen that the gps is not connected. Everything else works fine including the Cmap card reader. I called Humminbird to see if they had a gps receiver that was back compatible to my unit but they don't. I've been looking on the Internet for a used receiver with no luck so far.

Would any of you guys or gals have an old NS25 gps receiver (antenna) sitting around from an upgrade or know where I could get one

Thanks.