Hello all
I would just like to pop on here and give some pointers regarding a stuck Mercedes logo on your radio screen. I had this issue with my 2008 ML320 cdi and was on this site yesterday and it really helped me. Another member had posted something on this many moons ago...haha and with what he had posted and my testing it worked for me.

My W164 2008 ML320 cdi has the Harman Kardon system with the faceplate that ejects down so that you can place your music CD's in, or the upper DVD drive which is the Navigation CD. My Navigation never really worked well the whole time I have owned the vehicle (take special note to this!) My logo had been stuck on for two days with no controls working but the power button and volume control. The steering controls for the radio side did not work at all! I did however have sound but obviously stuck on whatever station it was last on which sucks. The actual faceplate would not go back into place after eject as well, I had to lightly force it up.....again stupid problem. So with some research on here and trouble shooting myself I found and fixed the issue.

So I see that this is a real issue in many makes and models of Mercedes but here is what I did and what worked. I first of course, checked all of the fuses and relays( which was not the issue), then tried unplugging the fuses with no avail as well. I then went to the GPS controller under the rear seat drivers side and unplugged the optical cable and let it sit for 15 minutes, this also did not work. I now was getting frustrated and decided to pull the positive terminal on the battery under the passenger front seat. Left it unplugged for about five minutes......again this did not work. I then pulled the whole radio unit out of the dash disassembled it and cleaned everything and yep you guessed it.......NOTHING, no go, did not work. Now I'm 4 hours in and pissed!!! Here is where I find myself back on this forum doing research and finding someone who had sourced a similar issue down to the DVD/Navigation unit (junk) haha. I figured "Hey, I'm going to remove the DVD/Navigation unit altogether and give that a try". Well holy sheep S__T it worked. haha.

If you do attempt this, taking out the radio is literally a 5-10 minute job. Just remove the top protective plate the is held on by 1 screw and there are 4 screws on the side of the upper DVD/NAVI unit and 2 screws near the front. Take the unit off the top and put the radio unit without the DVD/NAVI unit back into your vehicle, plug everything in and you are good to go.

 

Hi,

Welcome!
Thank you for taking the time to post the solution that worked for you!

Bob

 

This gave me hope and I tore into mine. It had been 3 days since stuck at the Logo on the control center, only power and volume work.
My testing that brought me to "my" problem. I saw one video that said Any Command connected device will cause the screen and controls to lock up.
Radio works, so amp, radio are fine, it's feeding data to my dash, that's fine. but still could be a single bad connection any place.
I was able to eject the CD drive, and glove box CD. so those might be okay,
I do have the intermediate cable to add ipod, looked solid, and was not standard - couldn't swap it out without cutting and soldering so, mehhh.
Then I read the OP post and watching a guy test components - I went back to the car and tried to eject the Nav DVD (and reset by holding the button pfft) did not eject, didn't even try.
Removed (only 4 screws on the side) the "navigation unit" (CD drive and circuit board in one housing) from the radio. Now all the music controls are back. I don't care about the nav system, so not having it is fine.
Fixed for free in less than an hour. beside the time I spent researching and pulling the nav system fully apart looking for issues that could be fixed.
This video was good to remove the entire system to work on it:

 

moved to W164 forum...

 

I went through everything that you did. Today I removed the nav unit. The command system is up and running again less the Nav unit. The nav cd was in the unit. It would not eject and the cooling fan was not running. I suspect there is no power to the unit? Wife is happy....has her radio and cd player back.

 

Hi guys I am still lost trying to find the navigation unit can any body tell me the steps

 

Went through system. Tried all suggested. The as one poster suggested removed NAV unit from dash. Volia now all is back as normal. Well except nav. NAV CD stuck in unit. ? Seems like it lost all power. Oh well on to other projects. Thanks Everyone.

 

thank you to whoever started this thread! My 2006 R500 had the same issue! I pulled the command out, removed the dvd drive with a few screws and I’m back in business!
Here are a couple pics for those confused about “removing nav”. You are actually removing the dvd drive from the command. After removing the screws, it pulls out from the back.