Audi Concert Single Cd - Problem

[kardo5o]

My Audi A4 Avant 1.9tdi has an audi concert radio with single cd. Sometimes, when I turn on/off car ignition the radio turns on/off simultaneously (normal). The problem is that, sometimes, when the radio turns on/off i heard some noise within cd player like some kind of vibration. In attach you can hear the sound vibration.
What it could be? Any ideas?
Thanks in advanced
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[a4tdi]

I have got exactly same problem. It seems to appear around 30°C+ outside temperature or stopping the car by breaking very hard, but I am not sure if these are the conditions to reproduce the problem.

It seems, that sensors or ****ysis of them think they have to load/unload CD at same time even there is no CD. This generates same sound as yours and like my Audi A4 Avant 1.9tdi. Often, turn off/on of Concert helps for the meanwhile. Pressing unload to unload an CD worked also. With no CD only off/on helped.

There may be certain conditions where the Audi Concert interprets signals wrongly, but what are they exactly?

Does anyone knows how the sensors work?
Mechanics: accelartion of mass or temperature may have effects?
Optoelektronics: dust etc. may have effect?

Audi garage may only helps me (car is still in waranty period) with an stable failure which I can present them, how does yours?

Thanks