Help with troubleshooting this DAC

[atupi]

Hi,

i've finished building the DAC described here:Audio DAC | wakalixes:FX
Page is in german but google translate works quite well.
and this is the overview of the DAC:


I have flashed the sotware and i receive massaes on display but no matter how i provide the signal (USB SPDIF or optical) the DAC shows all the time on display the message "No signal" (Kein signal).

Could someone more knowledgeable to help me to troubleshoot stage by stage why this is happening as i'm not so good in digital circuits to follow.
Of course i've wrote some emails to the guy who published the project but no aswer.

Thanks,
Adrian

[oshifis]

It is sure the problem is around the CS8416

[atupi]

I suspect the same. Attached the input stage.

When i press the SOURCE button i see that source is changing on display. Could be this possible even if let's say the communication between Atmega and CS8416 would be interrupted ?

I will check again the SPI connections between Atmega and CS8416

Any other clues?