won't take off

My quadcopter is Eachine QX95 , Reciever is X6B and the transmitter is FS I6 . I am facing a problem ,where when I throttle , the drone make a brief takeoff and then just lands and gets unarmed automatically and I had to arm again and again and again and all I am getting is a short 5-10 cm...

My Syma x8c fell into about 6 inches of water, just enough to get water in the main compartment. When I try to fly it now, it won't take off. All the propellers seem to work, but they only rotate for a second before cutting off, at which point the bottom LED lights start to blink (similar to the...

I decided to build a quadcopter in my spare time... after 'completion' I decided to test it out, but it would not lift off. Need some suggestions, based on my quad build: HobbyKing X650f frame kk2.1 flight controller Q Brain 4 x 25A ESC (modified the wiring to meet the layout of the kk2.1...