NavNet3D MFD12 No Chart Display

[StevenBC]

I am trying to troubleshoot my NavNet3D as to why it will not display any chart that is installed.
Thinking it a GPS problem, I looked up the GPS status page in the menu and did find that no satellites are being received and that the screen is blank.

I further went to check status of installed charts and found all charts installed and unlocked. So, I assume no fault there.
I have looked this forum over and cannot seem to find any information about the "mushroom" antenna that is installed on my boat
It's strange to me, that the plotter will show ships position (Icon on screen) and waypoints but will not display a chart. These objects are displayed on just a gray colored background.
Additionally, the plotter is not receiving any Lat/Long information nor displaying speed info in the information boxes on the main screen. This, of course is driving my autopilot crazy and is a big concern as I am always singlehanding my boat.

At the top of the main screen, on the status bar, The GPS symbol is also marked inactive with a red slash through the icon.
This problem was intermittent during the my first two years of operation on this boat. During that time, if this problem arose, I could usually remedy it by rebooting the system or moving the range all the way in or out. Not anymore.

The system was installed new in 2008 and I have owned the boat since 2018.

I am leaning toward thinking that the Furuno "Mushroom" GPS antenna is no longer usable. I have checked all connections and pins on the back of the plotter housing and found no corrosion/loose connections. I have also verified that the plotter is receiving information from the antenna in the correct port. This was verified by going back through the setup menu. The plotter has never been (since I've had it) exposed to weather and has always been sealed inside of a pedestal enclosure at the helm which is also covered.
I have tried everything I know to do and now at a loss as to my next step in determining what the problem is. I have considered just replacing the antenna (if I can find one) and do not know how to electrically troubleshoot it, but hate diagnosing a problem by just replacing parts.

Can anyone give me some information on how to determine if the antenna is indeed bad or have any other ideas or suggestions on something I may be missing?

 

[Johnny Electron]

Tell me a little about the GPS antenna. Is this a NMEA 2000 antenna that connects to the 2000 bus or to the radar connection up in the radar, or is this an 0183 antenna. Does it connect to data 1? You said you verified data on the plotter was being received from the antenna. How did you do that? I am sure we can get this figured out pretty easily.

 

[StevenBC]

Thank you for your confidence and reply.
I probably failed to make myself clearer about my haphazard diagnosing abilities.
On my unit, in the "Systems" menu, it seems that I am given a choice to select which port the antenna is attached to.
This is what I verified by looking at the back of the unit to see where the antenna cable was attached. As you probably know, the ports are labeled (Port 1, Port 2 etc.).

I am not sure what type of antenna this "mushroom" is. And it may in fact, be an antenna connected from the Furuno Navpilot. I have no radar on my boat.
I have been assuming that since I could not display a chart, that it is the chartplotter at fault.
The Navpilot WILL steer a course if I set it. But alarms every 3 minutes with an error message that there is no speed data. I assumed it was getting this data from the GPS antenna through the chart plotter.

I had a chance to do more troubleshooting this morning.

On the chart plotter menu, Menu<Charts<Data Catalog screen are listed my installed charts.
(which are listed as included). Raster, Vector, Satellite etc.
I have always used the Raster Charts.

When choosing a data catalog, the applicable chart is displayed on the right of the screen. (which is now just blue/grey)
I noticed there is a data box in the left corner of the chart displayed that gives range and an icon that turns red if that particular range chart is not available. I found that by selecting a smaller range that a chart will come into view. So I thought I had discovered the problem. However, when exiting the menu back to the operating display, I get the same problem. Just ship and waypoint icons displayed on a blue/grey background. Adjusting the range in the top left databox, does adjust the range. But it still does not bring in the chart. Additionally, on the main operating screen, I am still getting the red warning chart icon that the chart is not available. Adjust the range has no effect on this screen.

 

[Johnny Electron]

I think you would gain more ground in shorter time by calling our tech support while you are at the boat. While I am sure I could help you, it might take 100 posts and many days. I recommend you not investigate charts until you verify that the GPS is working well. Charts pretty much need GPS to place the boat properly and send the speed over to your autopilot. If you don't know what GPS you have or what port it is connected then it makes it hard to assist. A Furuno phone tech might be able to make some logical guesses by running you through assorted steps. Doing that here would take a great deal of time compared to talking to someone on the phone.

 

[StevenBC]

Thank You. I agree. Now if I can find that number...

 

[Johnny Electron]

Furuno USA support numbers are 410-479-4420 or 360-834-9300.