throttle down, idle up off, f-mode off, battery charged, flaps in the up position, there is a lot that can be the issue but it should tell you what the alarm is on the screen. My DX8 does anyway.
2nd what tony put f-mode switch in 0 position it is a fail safe on the tx just like the dx8 which i have also it is so if you turn the tx on and it is in stunt 2 -f-mode or also known as idle up 2 the heli does not take off real quick and cause injury or damage to anyone or anything...