80_six

Since the MB dealership said that something was wrong with the media interface unit itself, I decided to try and source a used part. I got one for like $68, and proceeded to drop the glove box and see about swapping the units out. After a bit of uncomfortable screwdriver-ing, the "new" unit was in -- only to have the same (non)thing happen. Power is still getting to the unit, but no information makes it from the interface to the car.

In the process, I noticed that one of the connections seemed to be fiber-optic. I imagine this is the one that relays information to the head unit or COMAND or whatever. So now I'm thinking that my media interface may be fine, but either a) the optic is interrupted somewhere or b) the software itself is corrupted somehow and unable to decipher or communicate.

Any suggestions? Can anyone who has a working unit take photos/video of the process of turning on and switching to the Aux/iPod source?

80_six

Also, is there a way to bypass this stupid interface and install something else into the head unit? Are there any decent upgrade systems for audio or even incorporating Android?

80_six

FWIW this is the unit I tried to replace:

http://i.ebayimg.com/images/g/ewUAAO...Yu/s-l1600.jpg

Edit: I am learning some more about the fiber optic system. It seems like if there is a break in the system, people have lost (all) audio -- I, however, have all audio working fine except from this interface. I've noticed the red light coming from the connection that goes from the car into the unit, but I suppose I need to check whether or not the media interfaces themselves are putting out a light/connection. I think I can do this pretty easily; it should tell me if I really do have two bad units. So...stay tuned for that. Any suggestions welcome in the meantime.

80_six

So...I've confirmed that I have optical signal coming from both the cable and the unit. The unit is getting power, but still no audio.

What next??

Edit:
https://youtu.be/DMa8ivtJ0s8
https://youtu.be/BA-f99rSQ8A

80_six

Just gonna keep posting updates until someone knows what tf is going on.

So I checked all fuses relating to sound/COMAND system and all were good. Although I noticed that #67 ("Sound System") in the trunk was completely missing. Not sure if my car was just not optioned with something and thus didn't require it, but I just threw a 40A fuse in there and tested...to no avail. Not sure what I expected, as everything else works fine. I left all fuses out for like 10 min to see if it would reset somehow.

On that note: so I'm trying to read up on the MOST fiber optic system, and I am only halfway to getting it, but it sounds like most people experience sound going out on everything if something in the fiber optic loop gives out. In my case, I have left the entire media interface thing (referenced above) completely disconnected, and everything else (CD changer, music register, memory card, radio, satellite) works fine. Has my media unit been bypassed somewhere? If so, why is it still receiving an optic signal? Why is my media interface putting out a signal, but my COMAND isn't recognizing it?

The next thing is to maybe check the head unit connections. Not sure what to look for there... But I have to replace my click wheel thing in the center console so I'll be tearing into everything anyway.

But is this possibly just a software thing? Should I even be messing with the hardware?

80_six

Welp. Now it seems like, just today, my Memory Card and Satellite Radio are out ("No memory card," "No device available"). Wtf it's getting worse. I used the memory card just last night.

Rudeney

No, there is not. Your options are to use a cassette adapter, or replace the head unit with an aftermarket radio.