onkyo 575 no saund repair

[semen1234]

in mi onkyo 575 cpu mpd780208 send comand -mute- all the time
i dont find the rizon, but if cut this "wire" in on condition of receiver
saund, appear and all work correct.
i vont cut this wire by additional relay connectin thear coil paralel to front
speaker relay if cut this wire at all- receiver dont dont start work after off.
excuse me for my english.