I have a Phantom 3 Standard that I was flying with Litchi software. Now when I power up, lights come on, cammera aligns, but blades will not engage. I hear a clicking sound from the drone every 3 sedonds.
Drone is turning on normally but your remote is not connecting to it. Are you logged into GO and connected through wifi? Others here may be of more help with that model, also YouTube.
A clicking sound from the ESC (Electronic Speed Controller) on a DJI Phantom 3 Standard likely indicates a motor or ESC issue. This can be caused by damaged motors, burnt ESC components, or even a problem with the mainboard.