Need help!!!! Stealerships clueless

[328eye]

I recently purchased a 04' 545i from a local lot and there was one issue with the car there is no audio and the car is showing a permanent mute button i tried unmuting to no avail and ive tried multiple things
Unplugged battery and let sit
Unplugged ccc
My amp current and old have the red MOST light coming from it aswell
Purchased and installed new logic 7 amplifier which is a 05 amplifer one year newer doesnt need coding just plug and olay so returning which is set up for next week
I was wondering if i had a bad tcu unit or something stopping the MOST fiber optic from going through all things there isnt too much online with my specifics, there is no sound whatsoever no open door sounds or seat belt dinging or gong when getting in nothing and i truthfully need help i feel like im in a hole with no escape from 0 sound

I also have the issue saying SOS call malfunction but i can still press and talk to a represenative

[ptarditi]

So a BMW dealer scanned this, with BMW Ista/d and saw all the modules responding normally?

[Jonny008]

Most likely the most bus is not completing a full loop known as a ring break just because there is light at the amp does not mean light is going to all modules in the most bus. A test is to jump the most bus at each control unit and see if communication is restored to individule control units.