I have two Eachine E010 drones. One drone (green color) stayed outside for a night with rain. I inspected the circuit board and it shows no damage: no cut cables that I could solder, nothing corroded. Both the transmitter and the drone turn on and show light but the transmitter does not control the drone. I turn both on within 2 seconds of each other, push the left lever up and down and the transmitter beeps, but the controls have no effect. (Note: when the drone is turned off, the transmitter has the same behavior: beep when I push up, flashing light, beep when I push down, steady light, so the beeps do not indicate binding with the drone.)
The other drone (red color) works fine. The green transmitter can control the red drone, but neither transmitter can control the green drone. I could not find a way to reset both to factory settings.
What could have gone wrong, and how to fix it?
Update: Here are pictures of the drone. The drone was powered while in the rain: a child left it on a house roof upside down and I realized and took it the next day after a night of rain.