80_six

Hi all,

So...I posted this over in the W204 area but have so far not gotten much help over there, so hopefully this area will garner some more specific support.

I'll try to be brief, but I bought this 2011 C350 Sport (US) used back in September. It's equipped with some sort of media interface that came with a stock auxiliary/30-pin iPod connector in the glove box, and it hasn't worked since I got it -- the COMAND just doesn't register anything as being there, so no sound. Some things I know:

1. The media interface unit is getting both power and optical signal from the car: both the cord into the unit and the unit itself gives the blinking red fiber optic signal when the car is started up.
2. Everything else (AM/FM radio, Satellite, CD changer, Music Register, Memory Card) worked fine and produced audio. (Caveat, just this morning the Satellite gave me a "No Device Detected" and the Memory Card threw a "No Memory Card / No Playable Files" error. I was just using the Memory Card last night, the last time I drove it. See below.)
3. I pulled all fuses relating to COMAND or sound and left them out for ~10 min and reinstalled. I noticed that my fuse #67 ("Sound System") in the trunk was nonexistent. Unsure if it was supposed to have one or not, I installed on to the correct spec last night with no change. The Memory Card (mentioned above) worked fine when I parked it last night, but doesn't this morning. Not sure if related to the fuse issue, but it's the only thing I've really changed. I removed the fuse again when I got to work, so we'll see if it reverts? (Not hopeful.)
4. I was reading that if any unit in the fiber optic loop is out, then the system won't produce audio -- however, for the majority of the time all of the components worked even with the media interface thing completely unhooked (I dropped the glove box to inspect it, see next item).

So I'm not sure what to look for from here. I have to tear into the center console to replace the infamous click wheel thing anyway, so I may just pop out the head unit and check out the connections in the back (what should I look for?) as well. Are the fiber optics messed up somewhere? Is it another piece of the system? Help plz.

(For what it's worth, I've had it to a nearby dealer a couple brief times, the last time they told me it was the media interface unit "a $900 part from Germany" but I have now tried two units in there with no difference.)

Does anyone have a schematic or more information on this system, and its components? And how to troubleshoot?

Edit: Here's the original thread: https://mbworld.org/forums/c-class-w...ipod-help.html

80_six

Anybody? Halp?