title_body: Holy Stone HS110D Drone PCB Wiring - What does the circled wire in the picture do? Total drone noob here so please bear with me. I bought my first cheap drone and I crashed it while flying indoor and one of the rotors stopped working so I took it apart to replace the rotor. But then I saw this black wire (please refer to the red circle in the attached picture) sticking out and one end of this wire not soldered to anything on the PCB.
  
  So my conclusion was either one end of soldering came off while I was taking the PCB apart or it wasn't connected to anything to begin with! So I would like to know the purpose of this wire and which one of my conclusion is right?
  
  And if it was soldered to something please guide me where to solder it back. Thanks for your time in advance. I would really appreciate the help!
upvoted_answer: That is almost certainly the antenna and one end is supposed to be free. This is increasingly likely as the square black chip next to it (labelled PAN159CY) is the wireless transciever (radio) - and I can't see another antenna candidate or connector.