title_body: How to debug a non-working Eachine E010?
upvoted_answer: The beep from the transmitter indicates that it has linked successfully with the receiver on the drone, so at least part of the board is working. However without detailed knowledge of the design and a range of test tools it will be very hard to trace the fault accurately. Even if you did, you need specialist soldering tools to replace tiny surface mounted components, and the fault may be in a chip with proprietary firmware (i.e. not available for sale).
  Really the only type of repair you could do is to replace the entire board, but I'm not sure they're available and given the price of these things I think you'd be best to buy a whole new drone and keep the frame, motors and props as spares because they are the parts that usually break.
  
  What could have gone wrong
  
  If it was wet when the battery was connected, it's likely that the water formed a galvanic cell between the copper traces of the circuit board and some of the other metals in the solder and component legs and cases. Galvanic corrosion is much faster than ordinary corrosion, and has probably caused an open circuit somewhere.
  The other option is a short circuit that generated enough heat to melt some solder and break a connection.
  If you dried it thoroughly before reconnecting the battery, then you did everything you could have, and that's normally enough - but small drones are made with the cheapest components and quality control is minimal, and sometimes they do just die unexpectedly.