murman

Hi there.

In the MB instructions for installing a CD changer into a W211

(http://ww2.justanswer.com/uploads/Ch...CD_changer.pdf)

At step 8, the following is noted:

"When replacing the CD changer (A2/6) up to generation Q4 with a CD changer as of generation Q5 (arrow), an adapter (16) must be inserted into the fiber optic cable connector (2). The adapter (16) is available as a
replacement part."

My questions:

1) what are these "generation Q4, etc." references. How do these differ within the same CD changer model (i.e. MH-3510)?

2) what is the purpose of the adapter? What would it's part # be?

Thanks!

murman

Anybody?

Polar Bear

I am sure they are revisions of the hardware, but I am unsure of the design changes between them. My changer was replaced under warranty due to skipping as it would randomly skip for no reason, on new, pressed, Audio CDs. It would do this in different locations of the tracks at random. I could reverse the song and play the same passage over, and it would not skip then.

Are you retrofitting or replacing a changer? I would assume the part number would be easy to locate in EPC.

murman

I've been trying to retrofit, but the last few changers I've tried have all had the same audio problems, and I am beginning to wonder if the problem might also be traced to the lack of the noted adapter... only changer audio is affected, not the rest of the audio system (i.e. aux, radio, comand cd slot...).

Polar Bear

It's possible, but interesting at the same time. As you know, the audio travels through a fiber ring, so the COMAND CD slow is thrown onto the fiber ring as well as the AUX when converted to digital. All of this would need to go though the CD Changer and back to the NAV processor, phone, SDARS, (if you have these) and to the AGW. What audio symptoms do you have? Have you version coded the AGW to set these devices in the MOST ring in the correct order?

murman

Yes, it's very odd that only the CD changer is acting up, but two changers have manifested the same issue, so I'm really stumped. Here's the history:

Version coding was done by MB when I first installed a CD changer. Audio was never a problem with the original changer.

Had to replace original changer when it went defective.

First replacement changer periodically manifested intermittent phasing and flipping between stereo and mono.

Second replacement changer's doing the exact same thing.

What are my chances that two changers would manifest the same audio problem?

Polar Bear

It sounds to me like it could be an AGW issue. I would not think that two changers would do this since it is essentially reading the digital CD-Audio data and passing it to the MOST. It sounds like either a connector is bad (which may indeed be the one that you asked about, but that still doesn't make sense if there are not other MOST issues) or perhaps the AGW is having problems.

Do you just notice that the music goes mono as it sounds dull? When you flip to another source does it sound better? What do the BAL/FAD controls do when it is doing this?

There could be an AGW software update for your car. You might be able to call up the AGW software from Engineering Mode on the HU - I will check and see on my car and see if I can get it to display that information without an SDS.

murman

The sound glitch drops in and out so randomly, that's it's been almost impossible to diagnose. It's not like it switches and stays screwed up for a long time; it glitches randomly. Some days, it doesn't glitch at all.

Broly

not sure if murman even visits this forum anymore. i found his name hilarious.

anyways, unsurprisingly, he had the same question i did: what in The Lord's name is Mercedes referencing when they mention the "generation" of the CD changer.

i have finally found a Q5 unit in the wild, from the motherland. it is OLD.

so the "generation Q[x]" is BASS ackwards. Q1 is the newest generation, Q5 the oldest. thanks to konigstiger, i figured out that it goes from MH3510->MH3511->MH3512.

i suspect EU units are MH3210->MH3211->MH3212 (or maybe they moved to MH3512, who knows):

murman

I don't visit the site much anymore, even though I still have my 2004 S211 with 170,000 km on it.

Murman? The ladies back in my university days called me that, and it kind of stuck as a nickname. Much better than some of the other names I should more rightly be called.

Back on topic, the more recent the CD drive, the more likely it will be mp3 compatible. I'd have to dig through old info to figure out how that was designated. It might actually be labeled as such on the unit, but it's been a long time and I'm not entirely sure.

Broly

so your nickname predated zoolander? :P i understand that would be "merman" but i thought they meant the same thing.

Q5 does not exist for US vehicle, i don't think. i could only find Q4 and i believe that was the changer a2118700889