Like many others I experienced a failure of the Vantage Vue temperature/humidity sensor. This resulted in a temperature reading of -67.8C. This first started shortly BEFORE my 1 year warranty expired however, when the weather turned cold (below freezing) the unit started working again. I live in Atlantic Canada however I'm easily 30 or so km from any sea water (which has been attributed to issues with numerous devices).
Anyways after my warranty had expired, the unit started acting up again. I had tried all kinds of things after reading forums, re-pairing, changing the battery, etc but nothing made any difference at all. I was pretty confident the issue was the sensors and not the base station though I had no sure way to test. I went basically all summer without my weather station functioning. I had it down and brought it inside a few times, set the components out in the sun to may dry out, etc. A few days ago I decided that I was either going to fix it or really truly justify buying a new one, here is what I did:
I took the white top/cover off (just the 4 screws accessible from the bottom side, no need to remove the wind vane) and then removed the temperature/humidity sensor (it sits at the 'back' of the unit under a little black cover which you can easily remove by squeezing two tabs and lifting it out of the way)
What I found was a sensor that had some obvious defects in the rubber casting and what appeared to be separation between the board and the rubber:
*Note I had started to peel the rubber off one end in the last couple photos
Notice the separation around the "top" of where the wire comes in to the unit and around the contacts on the bottom of the board for the plug.
Using a small screwdriver, a knife and my fingernails I was able to peel the most of the rubber off:
This was a tedious task that took some time, be careful you don't scratch any traces off the board.
Once the rubber was off the areas which the rubber was coming off of it was obvious there was moisture/some kind of oily film on the board (I could feel it on my fingers) All I simply did was rub it dry with my fingers/a piece a paper towel and then I tested it by putting the battery back in, sure enough it worked!
I removed the board again and sprayed it with electrical contact cleaner. I then sprayed the exposed areas with a couple of layers of spray silicone and re-assembled the unit and re-installed it. After being many months without the weather station I'm quite glad to have it back and functional.