Charging indicator lights do not work, the charger may overcharge

I have a Panasonic EY0110 battery charger that got a bit of water in it during a sudden shower. The charger still charges batteries but the indicator lights are not working and I have no idea if it is turning off at the end of the cycle or if it is over charging? I opened it up and can see no obvious shorts or burns, but I am beyond my depth. Is there a way to trouble shoot/ test the circuit board or is this a goner?