Problem solved! 
I had an issue in the setup() of the board: when you declare the Serial.begin() only for debugging test, the board wants the PC to communicate with...without it, the board can't go on and then stop there! 
Problem solved!
I had an issue in the setup() of the board: when you declare the Serial.begin() only for debugging test, the board wants the PC to communicate with...without it, the board can't go on and then stop there!