this is my first UAV build, so please don't bare with me :)
I use basically a S500 frame with 4S setup and a flightstack using a Holybro Kakute F7 1.5 FC, connected with a Holybro Tekko32 4in1 ESC board. Connected with the default 8pin bus cable and like the FrSky R-XSR RX wired up like the FC manual recommend (RX,TX and GND, 5V). Everything is working fine, if I connect LiPo and FC with USB.
Unfortunatly, the RX isn't powered, if I use only the LiPo. It's LEDs are just off and also the FC has only the green LED on, but not the blue one flashing.
I double checked the manuals and the web but have no idea whats the problem. There is a B+ cable within the bus to share full Bat power from ESC to FC but why is the 5V down? And why is there a different beep sequence?