I've got a NAD T761. Today I connected it to my computer with a digital coax cable. The Sound worked great until I did some config in VLC media player. I svitched from 5.1 to A/52 over S/PDIF (Dont know what it is). Then some strange sound appears... After that the sound did not work any longer... not even radio... Somone know what's the problem and know how to fix it ?