Started up the car at morning and found that there is no sound from the speakers. MMI fully working, playing tracks on CD/SD/smartphone, counting down seconds, but no sound at all, same with radio, TV, nav and even no beeping in parking mode. I've checked "playback settings" and there was no active presets for Bose, mean MMI just can't detect any audio system. Restarted MMI with "Menu+center+upper right" 10 times =) but nothing changed. I've called my friend at dealer workshop, he said that some times bose sound module can just fail without any reason and it will be replaced by audi for free ofc, but it need to be diagnosted with reading error codes and stuff to confirm warranty replacement with german audi office, so it's neccessary to connect my car to diagnostic tool with online data test, and i need to roll back to stock ECU program first (when i'm visiting dealer for maintenance my friend just disconnecting diagnostics stuff from internet, so ecu data is not going to online database, so for me chip + dealer doesn't mean TD1). I was kind of busy today and, actually, not in mood to driving trough heavy traffic to another part of Moscow for re-flashing back to stock =) But driving in silence just boring. I parked my car near house for couple hours at evening, and later, when i've go out to re-park my car to garage everything fixed by itself, sound playing perfectly, like nothing happened.

I've googled trough the forum and didn't find anything similar to my situation. May be someone had same problem before ? Should i visit dealer anyway and replace sound processor or just forget about it ?

Tnx.