2006 Suburban no audio and RSA turns radio on and off
 

Hey y’all, I have a 06 Suburban with Nav unit from Factory. Previous owner had aftermarket radio and it was stolen so I am switching to OEM. After buying and unlocking it I have had no sound for 2-3 months. I read another form saying the RSA has to be turned on at all times. I turned it on and boom I have sound turn it off radio has no sound. I bought a new RSA and nothing. I am looking at the digital receiver later today. I’m trying to understand why the RSA has to be on for the radio sound to be on. I need some help on this