mbenzCL55

As of 2 days ago, my audio has been not working, I get the display screen and the navigation works and can switch through radio stations select cassette etc, but don't get audio. The audio is amazing when it works (stock) but randomly started going out recently. I have to give it a smack and turn it off\on to get it to work, I'm thinking an audio input cable is loose in the back? Any suggestions?

awiner

Sounds like something is amiss in the fiber ring (or the amp is starting to become flaky). I would suggest having it diagnosed with Mercedes Star Diagnostics.

alx

You need das to diag the optical ring. Alternatively you can remove the head unit and check the connectors in the back. Your particular setup is prone to unplugging in the back as the secure connectors age and the locks break off.