Author Topic: Failed VP2 ISS Temperature Sensor  (Read 3980 times)

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Offline LABob

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Failed VP2 ISS Temperature Sensor
« on: December 28, 2017, 01:21:10 PM »
The weirdest thing: The temp sensor in my VP2 ISS failed at exactly midnight of 12/26. You can even see it go wonky in the WU graphs. I tried disassembling the ISS and cleaning the screen and the sensor with distilled water, but it didn't revive the sensor. I know it's rare for the temperature side to fail, but what's really strange is how it's not a total failure and still sending temperatures that seem plausible, but are up to 20°F off. I ordered a new sensor, but I'm wondering if anything else could be causing it. The console reports receiving the ISS signals fine.

Offline LABob

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Re: Failed VP2 ISS Temperature Sensor
« Reply #1 on: December 28, 2017, 01:35:10 PM »
Current temp reported by ISS: 65.5°F
Actual temp inside ISS shield: 73.4°F (determined by thermocouple probe)

Offline CW2274

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Re: Failed VP2 ISS Temperature Sensor
« Reply #2 on: December 28, 2017, 01:53:44 PM »
I'd wait and see if the new sensor fixes the problem before moving on. BTW what sensor is in there now and what did you buy? It may make a difference on your temp/humidity.

Offline LABob

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Re: Failed VP2 ISS Temperature Sensor
« Reply #3 on: December 28, 2017, 02:00:02 PM »
It's the SHT11 in there now. I ordered the SHT31 from Scaled Instruments.

Offline CW2274

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Re: Failed VP2 ISS Temperature Sensor
« Reply #4 on: December 28, 2017, 02:02:12 PM »
Now you need to know the how old your ISS is so you can determine if you need the -0.9F offset to apply.

Offline LABob

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Re: Failed VP2 ISS Temperature Sensor
« Reply #5 on: December 28, 2017, 02:04:31 PM »
Yeah. It's the pre-2016 ISS. I just hope the issue is the sensor and not something else. I've never heard of one going bad by reporting "normal" temperatures that were just off by 10 - 20 degrees. It seems like all the reported failures are either dashes on the console or wildly bad temps, like -40°F when it's 90°F out.

Offline CW2274

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Re: Failed VP2 ISS Temperature Sensor
« Reply #6 on: December 28, 2017, 02:05:00 PM »
And just for visual clarification, that is indeed a minus symbol in front of the value.

Offline CW2274

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Re: Failed VP2 ISS Temperature Sensor
« Reply #7 on: December 28, 2017, 02:06:18 PM »
Yeah. It's the pre-2016 ISS. I just hope the issue is the sensor and not something else. I've never heard of one going bad by reporting "normal" temperatures that were just off by 10 - 20 degrees. It seems like all the reported failures are either dashes on the console or wildly bad temps, like -40°F when it's 90°F out.
Agreed. Lets get the new one first and go from there, no need borrowing trouble.

Offline LABob

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Re: Failed VP2 ISS Temperature Sensor
« Reply #8 on: December 30, 2017, 07:53:18 PM »
Agreed. Lets get the new one first and go from there, no need borrowing trouble.

Received the new sensor today. The problem remains. So there's a wasted $50. :sad:

Also tried a new CR123A cell in the ISS. That didn't make any difference either.

EDIT: Dang it! It's the ISS. I don't know why I didn't notice before, but the UV and solar have been reporting 0 since December 26 also.

What could make the ISS board fail suddenly and right at the stroke of midnight?
« Last Edit: December 30, 2017, 09:05:53 PM by LABob »

Offline CW2274

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Re: Failed VP2 ISS Temperature Sensor
« Reply #9 on: December 30, 2017, 09:18:57 PM »
Agreed. Lets get the new one first and go from there, no need borrowing trouble.
So there's a wasted $50. :sad:
BS. If your ISS is properly sited, you're gonna love the 31's performance compared to the 11...when we get the problem figured out.
 Now...

Offline LABob

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Re: Failed VP2 ISS Temperature Sensor
« Reply #10 on: December 30, 2017, 09:42:44 PM »
Here's the ISS PCB and supercap closeup.






Offline Mattk

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Re: Failed VP2 ISS Temperature Sensor
« Reply #11 on: December 30, 2017, 09:57:58 PM »
So is your humidity and wind speed/direction also dead?

Offline LABob

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Re: Failed VP2 ISS Temperature Sensor
« Reply #12 on: December 30, 2017, 10:01:16 PM »
Wind is fine because I have a separate transmitter for the anemometer on the roof. The humidity is difficult to tell because it's been very dry here the last couple of weeks. Seeing 18°F dew point isn't out of expected range. I expect it's wrong, but don't know for sure.

Offline Mattk

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Re: Failed VP2 ISS Temperature Sensor
« Reply #13 on: December 30, 2017, 10:09:36 PM »
So is it the entire board or is this transmission related? Have you tried another ID#

Offline LABob

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Re: Failed VP2 ISS Temperature Sensor
« Reply #14 on: December 30, 2017, 10:12:16 PM »
Not sure of the issue. It's been working without even a hiccup for 4 years in its current location. Nothing changed. It just stopped working at midnight 12/26. I noticed because the temperature jumped from 48° to 57° instantly and just held there for hours. After that it never varied much more than 5° either direction even though the air temps were swinging almost 40°.

Offline LABob

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Re: Failed VP2 ISS Temperature Sensor
« Reply #15 on: December 30, 2017, 11:55:15 PM »
I may have spoken too soon. I rebooted the console and I'm getting readings within 0.05°F of the thermocouple probe. The only thing stopping me from declaring victory is that this is the temperature range that it has been reporting the whole time it was broken AND I want to see sun and UV data from the ISS. If it turns out to be as simple as a console reboot I'll chalk it up to the disadvantage of having uptime measured in years.

Offline CW2274

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Re: Failed VP2 ISS Temperature Sensor
« Reply #16 on: December 31, 2017, 12:06:10 AM »
Welp, I'm keeping my fingers crossed for you, certainly not saying it can't be, but I've never heard of your problem before and I own both VP2 and Vue consoles, they've never needed rebooting.

Offline LABob

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Re: Failed VP2 ISS Temperature Sensor
« Reply #17 on: December 31, 2017, 12:15:32 AM »
Thanks for the good thoughts. It's a victory (at least temporarily). I put a bright flashlight on the solar sensor and the console showed a reading of 1345 W/m2. We're back online.

EDIT - I still suspect the console, but only because of failing at precisely midnight. There are 86400 seconds in one day, which puts the probability of a random failure happening precisely at midnight at 0.0000116 - possible, but remote. The ISS has no concept of time as far as I'm aware.
« Last Edit: December 31, 2017, 11:54:05 AM by LABob »

Offline LABob

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Re: Failed VP2 ISS Temperature Sensor
« Reply #18 on: January 01, 2018, 02:59:35 PM »
The console is freaking out. I was walking by the console and notice it was an hour and twenty minutes behind, so I went into setup mode and set the time. When I returned from setup mode the outside temperature was reading 10°F less than when I went into setup mode (see here). Now I can't get the temperature to read correctly. It's acting as if there's a 10° offset, but there's only a -0.9°F offset for the SHT31. I already tried removing all power and starting up again, but that didn't work.

I don't know what could cause it to fail like that. It's been on a UPS that protects against over/under voltage since I got it.
« Last Edit: January 01, 2018, 03:01:34 PM by LABob »

Offline LABob

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Re: Failed VP2 ISS Temperature Sensor
« Reply #19 on: January 01, 2018, 03:15:35 PM »
Interestingly, every time I remove all power to the unit the time moves ahead one hour the next time it's powered on.

Also worth noting, when the temperature and humidity are reading incorrectly, the console reports --- for solar and UV. A couple of reboots and the console is back to displaying proper temps and solar and UV. I tried taking the console out to the ISS in case of transmission/interference issues, but it didn't change the readings at all. Diagnostics screens look good with >97% good packets, transmission levels 40+. I don't know what to think.
« Last Edit: January 01, 2018, 03:35:55 PM by LABob »

Offline Mattk

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Re: Failed VP2 ISS Temperature Sensor
« Reply #20 on: January 01, 2018, 03:58:00 PM »
Console time will always slip when re-powered. To eliminate things have you tried setting a different Id#

Offline LABob

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Re: Failed VP2 ISS Temperature Sensor
« Reply #21 on: January 01, 2018, 03:59:39 PM »
That's my next plan. I'm currently testing whether new console batteries resolve the issue (unlikely).

Offline GregJ

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Re: Failed VP2 ISS Temperature Sensor
« Reply #22 on: January 01, 2018, 04:27:01 PM »
I'm coming to the party a little late here, but my temp sensor just failed on my 12 year VP2 last month.  Here's my story.....  A couple of years ago I purchased a spare system when my console was starting to flake out.  My site has fairly high traffic and I didn't want too much down time waiting for repairs or parts.  I swapped out the rain collector about 6 months ago when it started to fail.  Then when my temp sensor went out I swapped that out too.  I sent the whole system to Davis for their $149 refurb deal.  It came back like brand new.  New LCD in the console, new solar collector, complete rebuild of the rain collector, new temp/humidity sensor and they updated all the firmware.  My total downtime was about 5 minutes while I swapped out the parts and if I had done this part by part it probably would have cost me more.  Now I have essentially a brand new system.  I highly recommend their $149 refurb deal.  I have done this with other VP2 systems that I have a contract to support.

Thought I'd share,

Greg
Davis VP2 with VWS

"Everybody talks about the weather, but nobody does anything about it." -- Mark Twain

Offline CW2274

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Re: Failed VP2 ISS Temperature Sensor
« Reply #23 on: January 01, 2018, 04:43:14 PM »
Safe bet that no one on the forum has seen this before. I'm curious as to the fix, as I'm sure others are too. Please keep us advised.

Offline LABob

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Re: Failed VP2 ISS Temperature Sensor
« Reply #24 on: January 02, 2018, 09:44:26 PM »
So far no further hiccups. Is it conceivable that low console batteries could cause an issue even when powered by an adapter?

 

anything