Hard to say exactly what happened here- but I would like to offer two possible scenarios right off the bat-
1. The sensor may have been out of range of the display for awhile, and then would not transmit rain count during that time. However, the sensor will store the rainfall count and update the display console when the 2 units come in range again.
2. The activation switch for the rain gauge is magnetic- what may have happened is the that tipping bucket mechanism may have been "teetering" in the middle,causing the magnet to activate and deactivate the switch very rapidly before the bucket settles to one side. That would explain the reading with no associated "thunk" noise.
I would suggest slowly pouring water through to make the bucket tip twice (thunk...thunk..noise)- the display should read .02, this should confirm everything is operating properly. Let me know what you find. THanks!
Scenario 1 - Its doubtful this is happening. After I calibrated the 5-in-1, I reinstalled it up on the roof, and then powercycle both the 5-in-1 and the console. Not 20 minutes later, it was registering rain with blue skies and no wind...
I like Scenario 2, tho... I wonder if one of the adjustment screws got set too high before I got involved. This would do a similar thing where the magnet is teetering. But with all of my adjustments in\out, I think that I would have changed the rate or sensitivity and that hasn't been the case.
One thing that I've been considering is taking the "failed" 5-in-1 that I have and swapping out the rain sensors with my FIL's... Are the parts interchangeable like that ?