Chosen Solution
Why my fmu led lights on board is not power on and the main led light is solid purple?
According to this troubleshooting document [Solid Purple] Failsafe Mode: This mode will activate whenever vehicle encounters an issue during flight, such as losing manual control, a critically low battery, or an internal error. During failsafe mode, vehicle will attempt to return to its takeoff location, or may simply descend where it currently is. Did you check for preflight errors?
