First, let me say I will never buy another OS weather station. I have had so many problems over the years.
Lately, my rain gauge worked great.... as long as it wasn't raining.
It would then start to rain, work for a bit and die. After a few dry weeks, it would start to work again (after I did a re-acquire on the base station). Not good for a station that I don't see for months on end.
The fix was were the wires are soldered on the circuit board in the actual rain gauge. Those wires are covered with silicon sealant. And, that is the problem. Over time, the sealant shrinks and pulls away from the wires. This allows water to seep underneath the sealant and that causes your failure.
The fix is to remove the sealant (easy to do) and then just waterproof the wires with either nothing or some candle wax. That is the fix. It does not have to be complicated. Silicon Sealant is the curse. (there are better ways to waterproof things).
100mm of rain later, it is working fine.
Mike va3mw