I have a quadcopter x with kk flight controller controlled by flysky ct6B recently I was flying it but after some decent use I observed that during flight one of my arm or motor stops in mid air just like it is not getting enough voltage but when I check through voltmeter the voltage is 11.1v
My battery is bit old and suffered a lots of crash but is not puffed nor damaged.
And when quad crashes the motor which stopped in mid air (2nd) starts to beep again and and its ready for flight.
Any help guys??? 

Isn't there any skilled person in this forum??

Isn't there any skilled person in this forum??

Hi, I don't know much about KK boards.
Do you have any bullet connectors between the ESC and motors.?
Where did you check the voltage?

Try replacing ESC...

i a normal quad . with beta flight . this would be a issue with throttle calibration / min throttle  . What protocol are u using for the esc to fc communication .

Thnx guys my battery was strained out and my esc was not calibrated properly thnx it worked.