vcc definition

Hi im installing a new DYS VTX on my Tyrant S. I just hooked up the 3 coords (1. 5v in 2. GND 3. AV in) to the cables coming from the FC. This is the same way that both the tyrant s original VTX and a TBS unify were plugged in and worked. When I turned on power after plugging up this DYS, I...