RDP 139 - Screen Curser moving when boat is moving



I have recently bought a 2002 Pursuit 3000 Express fitted with a Furuno NavNet RDP139 Radar, Plotter and Fishfinder.

When navigating to a GOTO waypoint the plotter screen is constantly on the move so I am unable to keep my position in the center of the screen.

Hitting Center puts my position back in the center of the screen but the Curser seem to be always on the move at high speed so within a few seconds my actual position is off the screen.

BTW I am a total dummy when it comes to Radar, so maybe I have something wrong in the Radar setup which is giving me this grief using the plotter display.

So I need some help and hope to find some help here.

Why is the Curser moving ? Doesn't do it at my dock.
Does "Center" really mean, "keep my position in the Center of the screen ?

Thanks for any and all input.


Your cursor is moving for one or more reasons. The first reason could be that your unit has REALLY old software. The very first NavNet series one units had software that was very sensitive to trackball movements/vibrations and could cause cursor "float" issues. Second, you might have a worn out trackball assembly. Even with newer software, if your trackball assembly gets worn out, it will cause cursor float. I would recommend having the unit serviced by your local dealer or send the unit in to us for repair/software upgrade.
Thanks Johnny,

I have cleaned and checked the tracker ball assembly and it looks like the rollers and the ball are in very good condition.
Although the boat is 10 years old, it has had very little use, for example the engines have only 250 hours.
But it has stood on a lift in the Florida sun for all it's life.

I had already downloaded "NavNet Software Nav24 Cmap20 VGA09 BB08"
Is this the latest software for this unit ?

I intend to update the RDP 139 software as soon as I can.
The installed Furuno system has a serial port mounted in the cabin so I am hoping it will be easy to update the unit.
How would I find the current software version ?

BTW the local Furuno dealers, South Shore Marine, are not exactly very customer friendly at this time of the year.
Concentrating on selling new boats is their priority and naturally fitting new electronics to the new boats.
So the line for help is long and uncertain.

If the software upgrade does not cure the floating cursor I will be sending it in for service with yourselves.



I had already downloaded "NavNet Software Nav24 Cmap20 VGA09 BB08"
Is this the latest software for this unit ?

Yes, this is the newest version possible to be installed by a dealer/customer.
Thanks very much Johnny.
Can it be updated using the serial port or must I connect the PC to the Ethernet network ?
Checked the tracker ball out yesterday on a 16 mile run on Lake Erie.
If I keep a finger on the ball everything is normal, release the ball and the cursor floats up the screen.
Tracker ball unit is obviously worn.
How do I obtain a replacement ?
[BTW I am an electronic engineer so should be able to fit a replacement myself]

Thanks again for all your help. Great !