Radar Display issue

[Bayhouse]

2x TZT19F with DRS25AXT/6 - Was cruising to the fishing grounds (3.5hr trip) in the dark with the Port display full screen on Radar. On it's on, the display changed orientation from HU to NU. Ok, strange so press the 'button' and return to HU, all is good for a little while. Then changed again - on its own - to NU and started swinging back and forth. Cleaned the button display area. Tried a button press again, unresponsive and couldn't get the Furuno button to respond either, had to reset the TZT3.

All good for maybe 45 minutes, then it started to happen again. Changed the STBD display to full screen radar and while Port swung back and forth, STBD stayed on HU telling me the issue is isolated to the Port machine. Had to reset Port TZT3 again and then started fishing with the radar display shared with other components on the page. Didn't see the problem the rest of the day but also didn't have the radar in full screen.

Suggestions?

 

[FishTech]

Cleaning the screen was a good first idea.
Check your grounding. You might add a chassis ground connection if you are experiencing phantom touches, which it sounds like you are describing.
Ensure your NMEA 2000 power is isolated. I have seen non-isolated NMEA 2000 power cause phantom touches on systems in the "no so recent" past.

 

[Bayhouse]

Can you clarify, what does "...NMEA 2000 power is isolated" mean?

 

[FishTech]

If your vessel does not have a single 12VDC battery bank for everything, then you need to have an isolated power source for the NMEA2000. This is per the NMEA 0400 Installation Standards.
You can use something like the Intervolt SPCi121207 to make it easy. There are many brands that make them, just make sure it is a trusted brand.

 

[Bayhouse]

Back with an update. Fished 3 days this week, all departing/returning about the same time. First two trips, no problem but on the last day the phantom touches started again and we had a chance observe some things.

Started by cleaning the screen - several times, no luck
Tried a multi-page, and found that whatever screen was active there were phantom touches
No other devices impacted, including the same TZT3 on the STBD side
Did not cycle power this time
As the sun rose and we increased display brilliance, the problem went away. Really feel like this is the root issue.

Fishtech, All of my house loads are on a single 12VDC battery that is also the generator battery. I would assume that any N2K issue would also impact the other MFD and/or other devices on the network - I have had zero issues with the other equipment when this is happening.

 

[FishTech]

It is most likely that N2K problems would effect the first TZT to fully boot up and assume the role on handling NMEA 2000 communications. In the PGN output menu, you can see an opposing arrow symbol in the top right of the unit doing this.
Did you try either removing or adding chassis grounds?

 

[Bayhouse]

Hmmm.....The impacted TZT (Port) is always the second one started since Stbd is the chart master. However, I observed recently that the Port TZT boots faster, even if it's turned on after Stbd.

I guess the chart master has more to load and takes longer?
Is it possible that the faster boot time on Port sets it as the N2K comms master?
Do you have a pic of the 'opposing arrow symbol' you reference, i'm not tracking what you mean?

Both units have chassis grounds attached, I can remove them to see if it makes a difference.

 

[FishTech]

Here is a pic of the "opposing arrow" symbol that denotes the "data master" setting. It is indeed base don which unit boots up first. Nothing to do with what power button is pressed first. They all have different boot speeds. It does seem that the chart masters tend to be a bit slower on boot than the rest.

 

[Bayhouse]

Thanks, I'll look at this more closely when I'm on the boat next.

I'm still confused as to why this only seems to be an issue on one machine when brilliance is turned down low....

 

[Johnny Electron]

If your NMEA 2000 bus has an issue, the unit with the arrows will be the one doing the communications (Data Master) and will be the first one to not like any bus problem.

 

[Bayhouse]

Makes sense Johnny, but why would it happen only when brilliance is turned down....

 

[Johnny Electron]

Never heard of an issue associated with turning down the brilliance. The unit will use less current with the brilliance down so normally if one were to have an issue it would be when Brill is turned up pulling more current. If isolated to the one display, I would document the brilliance level where the issue happens and send it into the service center to be evaluated.