So.... I ordered an Apple carplay box for my W204. I went into engineering mode to check AUX and see if I needed to enable it, I did and did, Followed simple directions, All went well but now I have no sound on anything...radio, sat. CD....zero! HU looks to be fine, other than no sound. Reversed my AUX setting, but no change. Did a HU reset, soft reset with fuse removal, even took batt off for an hour. The HU must have a Batt on the main board to retain settings. All stations and other settings remained....only clock reset. Does anyone know what I can do besides go to the dealer? I'd love to see a list of all engineering settings and exactly what they pertain to. Some are easy to understand and others are not. I didn't mess with anything else. Either a different setting some how defaulted & changed, or the HU had a brain fart and I need to do a RAM clear.

Thanks