Hi, I bought a scarlett 2i4 2nd gen but by connecting it to the Mac, changing the sound input and output with scarlett 2i4 (USB) and connecting the monitors, I don't hear anything, neither an mp3 file or a project on Logic (clearly changing the settings audio there too). What is the problem?

-Mac (OS X El Capitan 10.11.6)
-Adam T7V
- Cordial CFM 3 MV cables
-Focusrite scarlett 2i4 2nd gen