Nexus NX2 wind transducer: how analyse defect and disassemble

glsf91

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I have a Nexus NX2 wind transducer connected to FDX NX2 server. Also depth and log is connected, which are working fine.

Before the winter I removed it from the boat in working state. Now I put it back and it is not working any more.

It shows just dashes on the display (same when it is not turning any more because lack of wind).

Also the leds on the server don't light up.

I thought maybe the connection of the cable is not good. But I doubt if this is the problem.

Because when I measure the yellow and white cables (disconnected from the server), I measure about 10 volts on both of the wires between this wires and gnd (screen).

I think this means that the transducer is receiving ground (screen) and +12v (green). And also the transducer is connected to yellow and white inside the boat. So the connection with the cable or the cable itself should not be the problem. Otherwise I should not measure 10V.

This could mean there is something defect in the transducer.

Any comments on this?

I have to make some effort to take this transducer down.

Then I want to connect this to the server again, to make sure nothing is wrong with the long cable and connection. But I cannot use the cable.

I want to connect with some wires the connector directly to the server. But I don't know the pin layout.

Does anyone now what the pin layout is of the connector attached to the transducer?

And does anyone know how to disassembly the transducer to look inside?

I have some electronics background.

And are the yellow and white cables a digital output or analog output?

Can somebody tell how this transducer is working?

(what will be the output on these yellow and white wires)

A lot of questions, but replacing it will cost a lot of money.

 

DSE

Member
181
2
I had mine go bad and was able to get help from Garmin, but this was right after they took over nexus. I ended up swapping it for a new one (about $120) and had to return the old one. Prior to that, using an o-scope, I think I figured out that the white wire is speed and the yellow is direction.

 

glsf91

New member
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I found the problem. On the print inside was some oxidation.

Maybe it is also better to replace the bearings now.

Does anyone know where to find these bearings?

 

WHK

Super Anarchist
1,611
91
Newport, RI
Someone could start a small business fixing the original Nexus transducers and do very well.

This spring I replaced a 10 year old nWind Race when the bearings froze. Garmin now has the gWind race which no longer has the discrete speed and direction outputs, but instead connect directly to the Nexus RS485 bus. The new transducer I purchased was defective and had to be returned - the alignment angle would drift randomly event though the shaft was locked with a screw through the center. Garmin did ship a replacement gave me the choice of charging my credit card and then reversing the charge when the old one was returned, rather than going up the mast an additional time to return the failed transducer. The warranty replacement works fine, but I see some lag in response from how the original Nexus transducer behaved.

This morning I was helping another anarchist who had the nWind and replace it with the Garmin gWind. Similarly, his new transducer gave random data, then died. We took a cable from the gWind race on my boat to his Nexus Server and it worked fine. I think Garmin has some quality control problems with the replacement transducers, but at least they are standing behind the product with warranty replacements. Bummer to have to go up the mast more than once though...

 

glsf91

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I found the pin diagram here.

You can easily move the back part of the connector a little bit and see the colors of the wires.

And how it is working here.

 

JeffR

Super Anarchist
2,728
3
Newport, RI
Wow you actually got it open and are fixing it? Damn, I tossed my old one in the bin. I am the "fellow anarchist" mentioned by WHK. I spoke to Garmin today and they are sending me a replacement. Definitely some kind of QA issue since WHK and I both got rotten tomatos.

FYI if you want to save yourself some headache when talking to Gramin, the old Nexus Wind transducers are referred to as NX2 Wind and NX2 Race Wind. nWind was an interim product by Garmin that was similar to gWind but with a different cable connector. (old Nexus connector vs. new Garmin connector)

The old Nexus transducers send an analog signal down that is processed in the server. The new Garmin transducers send a digital signal that goes directly to the Nexus Bus (not the Wind input)

If you call Garmin, try to talk to Jason, I found him most helpful.

Been a month of headaches for me since I got my Garmin replacement. Hoping the replacement-replacement works.

 

glsf91

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Opening was not very difficult but must be done with care. The 2 parts are glued together and you have to "break" it apart. With 2 screwdrivers this can be done.

Here you can see some pictures from inside.

There are also some guidance pins. So take apart the parts gently.

 
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SteveC

Member
67
1
This is a long shot but something is dead on the circuit board on mine. One of the encoder channels is working (yellow) but the other is not. 

Don't suppose anyone has a broken one I could salvage some components from?

Garmin want crazy money for a new one. over €1200.

 

Joakim

Super Anarchist
1,401
77
Finland
This is a long shot but something is dead on the circuit board on mine. One of the encoder channels is working (yellow) but the other is not. 

Don't suppose anyone has a broken one I could salvage some components from?

Garmin want crazy money for a new one. over €1200.
The classic Nexus/Silva wind transducer PCB is extremely simple and it has just a few basic components, which can be easily found from electronics parts suppliers.

Missing one signal could be due to missplaced optoreader. They should be 1-1.5 mm from the ball. Or the ball colouring could be worn out.

 

SteveC

Member
67
1
The classic Nexus/Silva wind transducer PCB is extremely simple and it has just a few basic components, which can be easily found from electronics parts suppliers.

Missing one signal could be due to missplaced optoreader. They should be 1-1.5 mm from the ball. Or the ball colouring could be worn out.
Thanks,

The ball is fine. I have a good understanding of electronics and have a test rig set up with a few LEDs showing the outputs from each channel on the encoder.

Next step is I'll swap the two sensors and see if the fault moves with them, I've a feeling one of the had died.

Only issue there is having searched, I can't find the component for sale anywhere or even a part number on it. 

It can be triggered by moving a finger close to it.

 

George Dewey

Super Anarchist
2,059
109
Charleston, SC
For the connector on the wind transducer mast cable:

Look straight at the connector, with the male pins on the top.

The top left pin is screen

The top right pin is green

The bottom left female pin is yellow

The bottom right female pin is white.

 
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chriggel

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The reason for the random wind angle data on those Garmin units is that they used the wrong (or not enough) glue to fix the sensor head to the horizontal tube. I had one where I could pull the whole thing out from the tube - it was just holding on to the cable... Before I found this out I spent days calibraiting and still had no success. I was lucky to get an old Nexus nWind race with proper built quality but as they have a different connector I had to change the mast cable (again...)
As an engineer I have to give my kudos to the guy (Janne?) who invented that ying-yang looking ball sensor. Quite ingenious! 

 

George Dewey

Super Anarchist
2,059
109
Charleston, SC
...

I was lucky to get an old Nexus nWind race with proper built quality but as they have a different connector I had to change the mast cable (again...)
 
You could have just changed the connector, on the transducer and/or the cable. The Sure Seal connector is a nice connector and it's readily available.

 

George Dewey

Super Anarchist
2,059
109
Charleston, SC
The reason for the random wind angle data on those Garmin units is that they used the wrong (or not enough) glue to fix the sensor head to the horizontal tube. I had one where I could pull the whole thing out from the tube - it was just holding on to the cable... Before I found this out I spent days calibraiting and still had no success. I was lucky to get an old Nexus nWind race with proper built quality but as they have a different connector I had to change the mast cable (again...)
As an engineer I have to give my kudos to the guy (Janne?) who invented that ying-yang looking ball sensor. Quite ingenious! 
BTW, Garmin recognized and fixed this issue. All gWind Race transducers now come with both a change in the epoxy and a set screw in the mounting of the upper head. There is pretty much no way the vertical can spin in the carbon tube.

Also, as to the older Nexus wind transducer mast cable, I just found out that there is an adapter cable available so you can use a gWind with the older cable without having to change the connector or cable yourself:

https://buy.garmin.com/en-US/US/p/149360#overview

If you have a newer Garmin cable with the little 4 pin M8 connector used on the Nexus bus and want to go to an older transducer with the larger connector, you can then get the connector and change it on the cable. 

 
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SteveC

Member
67
1
Also, as to the older Nexus wind transducer mast cable, I just found out that there is an adapter cable available so you can use a gWind with the older cable without having to change the connector or cable yourself:
Just got a gWind masthead working with a NX2 server - with the adapter you mentioned, what they don't tell you in any helpful way is you have to connect it to the network port (same loop as the displays) and not the wind input that the original NX wind transducer connects to. Apart from that it was pretty straightforward.

Haven't figured out if the calibration settings work yet, need a flat calm sea day for that.

 
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