tackling a no sound issue 2014 S60 T5 Premium Sound System

[azureblue]

Now that I have the nose job done on the 2014 S60, I'm moving onto a "no sound from sound system" problem. Sometimes. when I power up the radio, I will hear a pop from the speakers, but no sound. And sometimes I will hear a very faint and distorted sound with the volume cranked up. I have read that the audio gets from the head unit to the power amp, via fiber optics, and this could be the issue.

I understand the power amp is under the back seat, but I am looking for the seat bottom release, to get to it, and I can't find it. I will check voltage and see if the light pipe on that end, is lit up.

I am looking for a wiring diagram, too..

Any input would be appreciated