Navnet 1 Radar issue



I have two displays networked via a hub. There is also a stand alone chartplotter on the network and AutoPilot. Everything works exactly as it should at the beginning of the day but some time later, maybe a half hour or so, the radar no longer paints the screen. The background is there but it does not update with any image. I am pretty sure I can hear the radome spinning. It will not come back until the next day when the cycle repeats itself.

Both displays are removed each winter and re-installed each spring. This problem has been happening since re-installation.
If you are not getting any errors or alarms, then it sounds like you have a problem with the IF amp in the radar scanner or the SPU board in the display. If you have another display of the same size, I would recommend swapping the displays and configure them. If the problem goes away then the display that was running the radar has a problem. If swapping makes no difference, I highly suspect you have a problem with the IF amp board in the radar scanner. You would want to have it checked out.
Thanks Johnny.

I do not have another same size unit to try what you suggest.

What I did do is remove and re-attach all connections and have used the boat twice since then. Symptoms have expanded, and seem to occur at random. When powering up I always hear the two beeps but what happens after that is often a surprise. Sometimes the screen stays dark, sometimes it boots up normally but never paints a radar picture. This may stay this way until shutdown or sometimes I will get a picture sweep after some long period of time, say 20 minutes has passed. Other times it never sweeps, the radar screen just shows its background. If the unit starts normnally, the radar may shutdown later. I get the occasional alarm that there is no GPS fix or the heading senor is missing. This can be turned off and whatever condition the unit was in prior to the alarm it will return to.

The unit is networked via a Netgear hub to a 7" Navnet 1, Northstar 952 and Simrad AP22. All (now) old stuff that has performed very well together over the years. The 10" is Navionics and also has a video card. The 7" (CMAP) is a slave for the radar.
Please start by ensuring you have verified you have good power right to the back of the unit. Bad corrosion in a cable can cause voltage drops or limit your current to the point you display has power issues. If you have good power, then I would estimate your are having a power issue inside the display unit. I would recommend sending the display in for an evaluation or have your local authorized dealer evaluate it.