Easiest way to tell is to power up the heli just enough so that the blades are spinning and give the heli a twist to your left(holding it over your head). If it's working you will hear the tail motor speed up. The instruction manual has illustrations in it telling you what each pot does on the 3 in 1 board. For quick reference though the bottom one is for tail motor speed/ engagement, the middle controls the gain for the gyro, and the top one is for balance between the left and right input from the controller.