Please remove the 3-pin cable of Split and power up Split with the following TV-out and power cable as shown below individually. Also please connect VIDEO and GND cables to VTx or monitor/goggles to check if there is TV-out image.
If there is TV-Out image, that means the VIDEO cable didn't connect well. Please try another 3-pin cable.
If there is no TV-Out image, the TV-Out function might be damaged due to the reversed connection of positive and negative or some. In this case, PCB needs to be replaced.