ileventh

Hi All, I've been struggling for a month now with an audio issue on my 2013 Audi Q5 2.0L with Navigation Plus MMI. I get no sound when the audio source is my tuner, even though by all indications on the MMI display the tuner is working fine. All the stations are there, it shows the artist/song info, but absolutely no sound. This goes for both terrestrial and satellite (Sirius XM) radio. However, CD playback and Bluetooth audio streaming from my phone works perfectly, with no noticeable audio issues.

I've tried multiple MMI system resets, switching between Telephone/Bluetooth/CD/Nav/Radio, but no luck. I've checked all radio/MMI fuses, both front and back, with a DMM and they are all fine. I did a scan with my OBDEleven scanner and there were no faults found on the sound system or in any other systems in the car. I've reseated all the cables connecting to the tuner module. The MOST bus optical cables were all glowing as expected. I've done a full reset of the system to factory defaults. So far nothing has worked. My mechanic also did a full scan of the car with his scanner as well as a capacitive discharge and cannot find any issues either. He is recommending having the dealer do a GFF (Guided Fault Finding) scan and possible a SW update, but I'm worried there will be a large bill involved once I take the car to the dealer.

I've searched this and other message boards but haven't found anyone who has encountered this same set of symptoms. Any ideas on what to do?