dfordham

The love affair with my new '14 has ended, at least temporarily. I have lost the sound from all sources (Disc, IPOD, Radio, NAVI, BT). It was working, then crackled and went away. All the COMAND displays are fine, showing that music is playing but there is no sound.

Checked the fuse diagram and found 4 or 5 fuses associated with sound or radio. Was able to check all but one which I could not reach without tearing the trunk apart (definite design flaw).

Any ideas? I go to the dealer on Wed. The dealer is 60 miles away. I'd like to avoid the trip if I can. I fear this is going to turn into one of those multiple trip repairs, since they are unlikely to have the part in stock and will have to order from Germany.

Regards,
Don

E Classy

don, i wouldn't worry too much about this. it doesn't sound too complicated. did you try some simple troubleshooting first?

* there is a mute button on the steering wheel that cuts all volume (just checking )
* the COMAND unit can be rebooted to a default state via the 'system' menu

the service dept. can check all wiring and make repairs as needed. a regional warehouse ought to be able to send any needed parts that have failed.

good luck.

dfordham

Thanks for the reply.

The system is not muted.

I reset both from the COMAND menu and from the hidden Engineering Menu with no success.

Regards,
Don

E Classy

bummer. hopefully the dealer can make a quick fix out of it. sounds like something that happens when you loosen an input wire on an amp/receiver. you hear that crackling, etc.

PeterUbers

I feel for ya man, best of luck

belarus27

Could it be an amplifier that went wrong?

BenzV12

I am sorry to hear that about , if a fuse blows then you should see a warning message following
Anyway, you can reset Comand on your own w/o hassling engineering menu ,may be it works but there is no warranty it would not happen again .
I think paying a visit to dealer is a wise idea

dfordham

Sounds likely. I just hope they don't have to replace the whole COMAND unit. From past posts, I'm pretty sure they have to be shipped from Germany and can take some time.

Regards,
Don

E Classy

well, hold on - the HK system has it's own amplifier/processor and it is not the COMAND system head unit. your post reads like COMAND is operating normally, but without sound... this assumes you have P1?

i believe there is a member here called RNBRAD that is familiar with the audio system internals. i'd bet he could send some tips on how to check the amp connections.

Jeffy

My '06 C350 did that occasionally. It was a software glitch with the fiber optic system. Short-term, disconnecting the battery fixed it, but then you have redo your presets. The dealer updated my software and that fixed it.

Arrie

I thought there is an auxiliary amplifier in the P2 cars. In my car in the engineering menu there is a selection for the amp and auxiliary is selected.


The problem OP has could be a bad amp. This would explain why everything works but without sound.


A question to the OP: Do you still have the warning sounds the car is supposed to make, like the seat belt beeps if you start it up and don't buckle up? If all this is gone then it very well could be a bad amplifier.


Could also be something else as I had an issue with all sound disappearing after a software update and the fix was to revert back to an older software which still was newer than what I originally had.

dfordham

All the warning sounds still work.

Regards,
Don

Arrie

Then it probably is not the amplifier. Could be something with the head unit itself.

E Classy

don, please update us after the service visit. i'm betting on MOST-type fiber cable/connection issue. but i guess they'll just do a SW update and call it good, lol.

dfordham

I'm at the dealer now. As expected, the first thing they did was update the ecu and COMAND unit. Didn't work. They're in contact with MB now and suspecting the amp. It's getting ugly.

Regards,
Don

E Classy

any news?

dfordham

Nothing yet. They gave me a '14 C250 loaner and sent me home. At best it will be tomorrow before I get mine back, assuming MB agreed on their diagnosis and the part got overnighted and it turns out to be the problem. Sigh!

OT: This C250 sport sure makes me appreciate my E. The ride is bone-jarring, the interior is junk. The gas mileage is only slightly better. On the ride home from the dealer I got 29.8 mpg with the C, vs 28.0 on the way to the dealer with my E.

The engine is surprisingly responsive. This is the first turbo I've driven in my 67 years, and I am cannot get used to the lag from the single turbo. It's nearly impossible to accelerate smoothly with more than light throttle. When the turbo spools up, it kicks you in the pants.

Regards,
Don

E Classy

yeah, i stand by my claim that an accord is a better buy than a c-class.

which part did they order? amp?

dfordham

I think they called it the amplifier control module.

Regards,
Don

E Classy

sounds like that is the harman kardon logic 7 unit. usually those are in the trunk, with fiber cables (MOST) run to the head unit in the dash. the thing about the HK-L7 system, is that it kinda sounds like crap! wish they would ditch it and go with B&O, ML, or even Bose as the "premium" sound.

dfordham

Update:

As originally feared, the part they are convinced is the problem is not stocked in the US distribution centers, so it is on order from Germany.

Regards,
Don

E Classy

they waited a whole day to tell you that. not cool.

Arrie

Just a stupid comment here...


When I had the problem with lost audio I also lost all warning chimes. I though all sound in the car comes thru the speakers so if that is the case (?) how do the warning chimes work if the amp is bad?


Or are there different speakers for the Comand audio and car warning chimes?

mercedes4ever

No such thing as a stupid comment / question, if you don't ask you never know?

dfordham

I don't know, and I'm not sure my dealer's techs know either.

Regards,
Don