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Weather Station Hardware => Davis Instruments Weather Stations => Topic started by: d_l on December 23, 2017, 02:44:51 PM

Title: Interesting failure mode of Davis 6332 Anemometer Transmitter Kit
Post by: d_l on December 23, 2017, 02:44:51 PM
As most everyone knows, the Davis 6332 Anemometer Transmitter Kit can be used for more that just a relocation of the anemometer. If you are willing to shell out for the auxiliary sensors, you can turn the 6332 into a complete VP2 weather station.  Well I have done so for the past few years mainly to check wind speeds and temp/hum at a height above the ground boundary layer.  This arrangement also gives me some sensor redundancy.  See: https://www.tceweather.com/TCE26.html  (https://www.tceweather.com/TCE26.html) for photos of my set up.

To connect the 6830 temp/hum station on top of the flagpole, I used a 25ft RJ12 Modular Telephone Cord, 6 Conductor 6P6C and a Modular Inline, Straight Coupler 6P6C.  Recently this station started reporting temperatures of 158 °F and bizarre humidities during a heavy rainstorm, but all the other sensors were reporting correctly!  I thought maybe a power reboot of the 6332 would fix this problem, so I pulled the back up battery, disconnected the solar panel, turned on the test LED, and waited for its super capacitor to drain.  When I powered it back up, it was still reporting temps that varied over time from 158°F to -30°F.  So then I pulled the 6P6C cable from the temp/hum jack and the thing was still reporting crazy temperatures without any input to that jack! At that point, I decided that the 6332 was partially fried. 

I purchased a 6332 replacement gambling that there wasn't a problem with the 6830 temp/hum station, or the in between wiring. The new 6332 is working fine, but I haven't had any heavy rains, nor have I contacted Davis about this failure mode.  Just thought that some people might be interested in this peculiar failure.
Title: Re: Interesting failure mode of Davis 6332 Anemometer Transmitter Kit
Post by: eyecue on December 23, 2017, 10:41:32 PM
That is perplexing.  I  wish Davis would be more forthcoming with their design info or schematics.  I have even tried looking at the patents on the equipment to see what is out there. That was real mess because Davis has listed Lacrosse patents and it gets really  murky because there was a major lawsuit over infringement and a settlement etc.  But alas, no info that is useful.
Title: Re: Interesting failure mode of Davis 6332 Anemometer Transmitter Kit
Post by: reef on December 24, 2017, 07:36:48 AM
You know, in all this time I had no idea you could run more than just an anemometer from the wireless transmitter. I just assumed Davis used the same PCB for cost reasons. I've had my wireless transmitter for 7 years now and always wanted solar and UV sensors but didn't bother as I couldn't get them high enough when connected to the ISS. Does this mean I could have just connected them to the transmitter and put them up with the anemometer all along? You're right about info being more forthcoming because I had absolutely no clue this could be done! Doh!
Title: Re: Interesting failure mode of Davis 6332 Anemometer Transmitter Kit
Post by: johnd on December 24, 2017, 07:52:55 AM
Does this mean I could have just connected them to the transmitter and put them up with the anemometer all along?

No. While the PCB hardware is identical across several transmitters, the standard console can only receive data from one ISS. (solar/UV have to be on a transmitter configured as ISS).

NB For receivers like Envoy8X or Meteobridge Pro Red this limitation does not apply.
Title: Re: Interesting failure mode of Davis 6332 Anemometer Transmitter Kit
Post by: azchrisf on December 24, 2017, 11:11:43 AM
That is perplexing.  I  wish Davis would be more forthcoming with their design info or schematics.  I have even tried looking at the patents on the equipment to see what is out there. That was real mess because Davis has listed Lacrosse patents and it gets really  murky because there was a major lawsuit over infringement and a settlement etc.  But alas, no info that is useful.

The community is large and has quite a few electronics people, I'm sure they could easily trace the boards and write some documentation on them. That would be of major help to us all. I think it's just getting people organized...
Title: Re: Interesting failure mode of Davis 6332 Anemometer Transmitter Kit
Post by: EA1EF on December 24, 2017, 06:11:50 PM
Can try now to test your 6332 ISS, after several days for total drain the supercap. Years ago one ISS turn crazy and do not transmit. We put as broken, months after test and it work fine, it is working now two years after.

Can test with other sensor type for localize possible fails in board.  Wind,  temp sensor waterproof 10k, other temp/hum with shorter wire..., rain etc.

 It is typical fail in long wired sensors the serial SMD resistor in sensor input, near RJ11 100 ohms typical. This SMD resistor fail also in wind vane circuit near reed switch...

Also without sensors must receive info as battery check, led check status, etc.
Title: Re: Interesting failure mode of Davis 6332 Anemometer Transmitter Kit
Post by: d_l on December 25, 2017, 12:09:59 AM
Can try now to test your 6332 ISS, after several days for total drain the supercap. Years ago one ISS turn crazy and do not transmit. We put as broken, months after test and it work fine, it is working now two years after.

Can test with other sensor type for localize possible fails in board.  Wind,  temp sensor waterproof 10k, other temp/hum with shorter wire..., rain etc.

 It is typical fail in long wired sensors the serial SMD resistor in sensor input, near RJ11 100 ohms typical. This SMD resistor fail also in wind vane circuit near reed switch...

Also without sensors must receive info as battery check, led check status, etc.

I tried draining the super capacitor once to reboot the 6332 without any improvement of the temp/hum anomalies. As I stated earlier, all the other sensors were working perfectly while the temp/hum was haywire.  Unfortunately this is a production unit and I do not have a spare 6830 temp/hum station to use to experiment on it.
Title: Re: Interesting failure mode of Davis 6332 Anemometer Transmitter Kit
Post by: EA1EF on December 25, 2017, 10:36:22 AM
A cheap test is connect a 10K ntc thermistor in central pins temp hum rj11 connector. It cost 1 dollar in ebay, sould done temp readings... No more ideas if haven't sensor temp hum replace, belfryboy sold in 55 dollars I thing...
Title: Re: Interesting failure mode of Davis 6332 Anemometer Transmitter Kit
Post by: d_l on March 11, 2018, 01:58:17 PM
I examined the anemometer jack on the failed 6332 and noticed that some pins have missing gold plating.  The third from the right side (facing the jack) is the worst with about 40-60% missing plating and etched-looking copper showing.  The second from right side and the left most pins also showed spot areas of missing gold (~10% of the pin) and exposed copper.

There seemed to be some soldering flux(?) or some other goop on the outer plastic rim of the jack.

Once I had noticed this problem with the jack pins, I checked the 6P6C plug for gold loss, but it appeared to be intact.

Right now my working hypothesis is that condensation in the jack and on the plug during a spell of high humidity/rain bridged the adjacent contacts and set up a short circuit.  There also was electrolytic de-plating of the gold on the pins.  Spilled solder flux on the pins provided the electrolytes for the electrolytic cell and to make the bridging condensation conductive.

Well that's my story and I'm sticking to it.  :-)