The ESC shows no reaction
Check if battery is connected correctly
The LED(8) lights up after connecting the power plug but then stays off
Check Signal connection. When using PWM re-calibrate the ESC
The engine trundles only and does not rotate properly
Check the 3 motor connections (1) on contact (some motor cables are painted and must be stripped)
The Copter looses power after some time.
The ESC goes into its temperature protection. Reduce the load or give it more cooling.
The Copter jerks at full speed
1. the ESC might go to its over-current protection. In this case it reduces its max current to 40A. This reduction can confuse the FC. Please lower the load in this case.