On the Yamaha receiver and the Sony TV you need to select both the source and the destination of the Audio. I have a similar setup to yours and the Yamaha receiver was setup to pass the audio to the Sony TV rather than pass the audio out through the receiver. From memory, the TV needs to know about this as well.
I have found some incompatibilities between Yamaha and Sony but most could be fixed using the menus on both devices.
My D54250WYK passes full surround sound to my Yamaha receiver.
I hope this helps.
I have found the solution now.
I change the HDMI receiver input from DISPLAYPORT to HDMI out.
Deinstall graphics and audio drivers.
Install the last drivers from 5-3-2014.
Set the audio source setting from the Sony TV from GENERAL to HDMI.
And its works now.
Have audio and video on Sony tv and Yamaha receiver.