NMEA 2000/ Airmar DST 810 help

[jmh611]

Hi all, I've been a long time reader of the forums but never had an account. I'm currently running into some trouble with Garmin/ Airmar DST 810 triducer, and wanted to check with you guys on your thoughts.

Our first Airmar was installed about 3 months ago, the depth data would display flawlessly on our Garmin 1022 chartplotter at the Nav Table, but the depth data would intermittently disappear at the GNX10 at the steering pedestal in the cockpit. I assumed for some time that this was a GNX10 issue or NMEA2000 issue.

I troubleshooted all the standard NMEA2000 bits.

• NMEA network has 12+ volts.
• Our batteries are brand new Renogy LiFePO4 and there is 600aH capacity. We never have low batteries. This is not a voltage issue, or voltage surge issue. Everything runs off of a Victron Multiplus 3kW, and I've never had an over-voltage warning. And never experienced a failure on any other 12v device.
• I have never had a low voltage alarm go off on any of the NMEA devices.
• I have no problems/ intermittent issues with any other NMEA 2000 network device.
• There is 60ohms of resistance when testing Can-H and Can-L at various t-connectors throughout the boat with power turned off.
• When testing between Ground and Shield pins resistance is zero.
• This isn't a large or complicated NMEA 2000 network. See attached diagram.
• The NMEA power cable is fused with a 3A fuse.

Garmin recommended removing everything from the NMEA network, and just connecting the Airmar. Well this is where it got interesting, the NMEA2000 network fused, and after that the Airmar no longer worked at all. No data would appear at the Chartplotter or GNX10. And I could no longer see the Airmar via the Cast app on my iPhone. It had gone.

The NMEA2000 cable is hardwired into the Airmar so no way of doing any further testing. Garmin agreed. I sent it back and they shipped out a replacement.

Installed it a couple days ago, and we had depth, temperature data, etc all working again at both the Chartplotter and GNX10, I could calibrate the Airmar via the app.

We went out for dinner, came back, and all Airmar related data had ceased. And in fact I again could no longer see the Airmar via the Cast app again! But no fuse was blown.

Can it really be another faulty device? Or is there something else going on here? I've attached a diagram of our NMEA network, it isn't exactly complicated.

There are no other failures or data loss on the network.

• I have plugged the Airmar into various different t-connectors, and no Airmar power. I have plugged other devices into the t-connector the Airmar used to use, these devices haven't had any issues. Being autopilot, wind sensor, AIS.
• The NMEA power cable is fused with a 3A fuse. With the previous faulty Airmar DST810 the fuse blew twice, before never turning on again. With the new Airmar there has been no fuse blown, but it has stopped working.

Garmin are now suggesting I need a NMEA technician to come aboard and review the system, or an electrician. I don't see what this will add as I've followed NMEA guidelines/ installation instructions to the T as far as I know, and I don't want to just clock up further costs for an technician to come aboard and say yup, no problem with it. We don't have a lot of budget to spare.

So I thought I'd at least post here and have somebody check it over or throw out some ideas about what the problem could be!

EDIT: Not sure why but the image keeps being uploaded flipped upside down. I've tried rotating it on my computer and whatever I do it uploads upside down.

[TheOffice]

Two things to check - Is the AP also supplying power to the backbone? It should not. Why is there a ground on one end?

[cr180]

Like you, I installed my own NMEA 2000 network. You have already verified the two critical network parameters: 1) 12vdc power and 2) 60 ohm resistance in signal circuit. Furthermore, you have verified other devices work ok plugged into same terminal as depth transducer. Think network fine.

[cr180]

One other thought. You may be able to talk to Airmar Tech Support directly.

[jmh611]

Originally Posted by TheOffice

Two things to check - Is the AP also supplying power to the backbone? It should not. Why is there a ground on one end?

Thanks for replying! Wasn't sure what 'the AP' was? The backbone is powered via distribution panel on the nav table so that the NMEA2000 network can be switched off as needed.

Distribution panel itself is powered via 16mm2 cable direct from busbar after a Victron Multiplus 3kW.

I really don't think it can be a power issue, though as I have no other power related issues/ symptoms across any other NMEA2000 devices, or just any other 12v devices utilising the batteries.

EDIT: There is no ground on my diagram, those are the two NMEA male/ female terminators which I believe are needed to ensure the resistance is at 60ohms.

EDIT2: Assuming AP is autopilot? No the NMEA network is not powered by the AP. Hopefully answered above. The autopilot drive unit has its own power source via the Garmin ECU. The GHC50 (which is the Garmin unit for controlling the autopilot, setting course) is connected to the NMEA network, as is the Garmin CCU (compass).

[jmh611]

Originally Posted by cr180

One other thought. You may be able to talk to Airmar Tech Support directly.

I might give this a go if Garmin are going to start digging their heels in about replacing the 2nd unit.

[jmh611]

For some reason the edit button has disappeared on my original post. But here are some additional symptoms I have remembered.

We had both depth and temperature data at the chartplotter and GNX10. Then after an hour or two after installation the depth data disappeared, it never came back. But the temperature data still remained. I could see the Airmar in the Cast app on my iPhone but it wouldn't allow me to connect to the device, connection unsucessful.

Another hour or two passed, we went out for dinner. and when we came back the temperature data had now disappeared. And furthermore the Airmar wasn't visible in the Cast app anymore.

Its as if the device slowly killed itself in stages over a couple of hours.

I was wondering whether the device itself was potentially not watertight? And a tiny leak was getting in and slowly shorting the circuit? I don't know how these things are manufactured and whether that is possible or not. It was just strange how it slowly died over a few hours. It wasn't a total and immediate failure, it was a slow decline.

[goboatingnow]

I would conclude the airmar is faulty

[flee27]

I think maybe TheOffice is misreading your GND10 as the abbreviation for ground (gnd).

Please keep us updated on your finding and hopeful fix.

Foster

[OldGreyB]

I feel your pain with the DST810, but you are not alone.

Your experiences and listed symptoms are similar to myself and fellow cruiser here in Australia.

Fellow cruiser is on his third DST810 in five months. His first lasted 4 months and lost depth, while also blowing the network supply fuse. His second lasted 3 hours and then lost depth.

His serial numbers where: A0007SLE & A0009PHR

My first worked only for 36 hours then lost depth. Shutdown network, tested with known good DST800 - no issues with network or older DST800 version outputs.On repowering the SeatalkNG network & DST810, it completely failed to respond and would not be found by the CAST App

Was comfirmed to have prematurely failed by local agent.

Serial number : A0009PHW

My second DST810 is still working at two months, as at time of writing.

It would be interesting to have you post your failed DST810 serial number.

Request another one. You can use this post as a support, as there is a possible bad batch or design issue?

[jmh611]

Originally Posted by OldGreyB

I feel your pain with the DST810, but you are not alone.

Your experiences and listed symptoms are similar to myself and fellow cruiser here in Australia.

Fellow cruiser is on his third DST810 in five months. His first lasted 4 months and lost depth, while also blowing the network supply fuse. His second lasted 3 hours and then lost depth.

His serial numbers where: A0007SLE & A0009PHR

My first worked only for 36 hours then lost depth. Shutdown network, tested with known good DST800 - no issues with network or older DST800 version outputs.On repowering the SeatalkNG network & DST810, it completely failed to respond and would not be found by the CAST App

Was comfirmed to have prematurely failed by local agent.

Serial number : A0009PHW

My second DST810 is still working at two months, as at time of writing.

It would be interesting to have you post your failed DST810 serial number.

Request another one. You can use this post as a support, as there is a possible bad batch or design issue?

Thanks - this is very reasssuring.

• Serial number on first unit was A0007MBX
• Serial number on the second unit is A000ACS1 (this is the 2022 gen2 paddlewheel version that they replaced the 1st unit with)

I have shared this post with them, and am chasing daily. Hopefully they can see that this issue is not isolated. But I expect they already know that.

I've also got in touch with Airmar France (EU office), but they have just referred me to Airmar USA tech support team, although very apologetic about the issues I am having.

[jmh611]

Okay this is hilarious - Garmin have finally responded and in layman terms said that they will return the unit, but need to inspect it heavily. If there is another short circuit or similar in the device then they will not replace under warranty because it must be the fault of the NMEA network.

We give you a new RMA number to send us the DST 810, however this one we will have to analyze longer than the previous one before making any changes because if the new device is also short-circuited we will not be able to pass it as warranty.
If three devices connected to the same NMEA 2000 network are failing, then there is something wrong with that NMEA 2000 network.

My response below:

Thank you for responding, I will send the unit back as soon as possible.

What are the three devices that failed on the NMEA network?

There has been 1 failure of gWind which was not related to NMEA failure. The gWind mast head unit is not connected to the NMEA network. It is connected to the GND10. The GND10 is connected to the NMEA network and you sent this unit back to us because it was not broken. And I agree because it works with no problems. You replaced the gWind masthead unit and we have no problems since. The gWind failure has nothing to do with the NMEA network.

There have been 2 failures of a DST 810.

The first unit you have not verified how the unit failed. What inspection did you carry out? Was it a confirmed short circuit? What components in it have short circuited? Have you found the cause of the failure? If no, then we do not know whether it was a short circuit for sure, although it seems likely given that the DST blew the 3A fuse on my NMEA network.

How can an NMEA network short circuit and both times it is the DST 810 that fails? But no other NMEA device has failed. It would be impossible for a NMEA network to short circuit unless there was damaged and unsheathed cable because everything is otherwise isolated from each other via the pins.

Please explain how it could? Because I want to learn.

Between each new DST 810 unit I’ve installed them into different t-connectors. And the old t-connector is used for another NMEA device and hasn’t failed.

For both units to fail because of a problem on my NMEA network it would have to be an intermittent problem on multiple t-connectors, that somehow only effects the DST 810 but not any other NMEA device on the network.

Please explain how this could happen?

You can’t make the accusation that I have short circuited 3 units via the NMEA network. When 1 (gWind) was a totally different issue and not related to the NMEA network. The 1st DST failure you never confirmed the failure, and the 2nd DST failure we don’t know the cause yet.

Looking on the internet it is quite common for these units to fail. And it seems people have multiple failures.

We have been without a fully functioning depth sounder since we bought the product a couple of months ago and we have been very patient. I really don’t like having an accusation thrown at me when there is zero proof.

As a side note I am contacting Airmar directly and have asked them if this is a common failure. The Airmar France team have referred it to the USA team.

For additional context I bought a gWind wired unit with GND10 black box that converts the Nexus signal to NMEA 2000. The gWind unit died as we crossed Biscay, I sent both the gWind and GND10 unit back to Garmin. They replaced the gWind mast head unit, and sent back the old GND10. Since then it has worked with no issues.

So, I sent this email to Garmin just now and by coincidence Airmar USA responded to my query I sent out yesterday.

Hi Joe,

My colleague from the US has responded:

This sounds like very bad luck to be honest as he is very thorough in describing the electrical specifications of his boat and everything on the face of it seems fine.

Regards,

Neil

This is so frustrating. Makes Garmin look like a fool though.

[Sheet]

Did you find what was causing the transducers to fail and get a satisfactory resolution. We are having the same problem on a Garmin system. We replaced an older transducer that quit working with a new 810. It worked for a couple of days and quit. Got on the phone with Airmar and had a new 810 the next day. 2nd unit worked for a day but depth quit working on day 2. All measurements are within specs and no issues with 8 other N2000 components. Speed and temp still work. Will call Airmar again next week but was hopeful you found the problem.

[jmh611]

Originally Posted by Sheet

Did you find what was causing the transducers to fail and get a satisfactory resolution. We are having the same problem on a Garmin system. We replaced an older transducer that quit working with a new 810. It worked for a couple of days and quit. Got on the phone with Airmar and had a new 810 the next day. 2nd unit worked for a day but depth quit working on day 2. All measurements are within specs and no issues with 8 other N2000 components. Speed and temp still work. Will call Airmar again next week but was hopeful you found the problem.

We never found out, I'm afraid. Garmin did agree to replace all the units. And eventually we were sent a unit that worked, and we are a few months later now it has worked.

We still have an intermittent display of depth info on our GNX 20 at the helm station, even though all other data is displayed flawlessly. The depth + temperature data (from the transducer) intermittently cuts out, but continues to show on both OpenCPN, and the GPSMap 1022 charplotter. I think its a fault with the GNX 20, but I gave up complaining...Sounds like you had a very similiar problem to me though, its probably just another bad unit.

[OBXSkipper]

I wish I could help out Sheet but I'm just reviewing threads to gain some info. I really wish the OP's would come back and give "closure" to their threads...lol . It would really help and not specifically in this thread but in many. If OP's would being willing to even say" I never resolved this and had to replace it" , at least that would help.