HD audio not displaying on Receiver

Sounds like a software issue.

If you want to make sure, download a demo copy of TMT5 and see if DTS-HD MA or TrueHD lights up on your avr.

What is most likely happening is your PC is doing all of the encoding and passing it on to the 609 (the same AVR that I have by the way)

If you can figure out how to bitstream to the AVR, then the Onkyo should be doing the processing. Not sure if I explained that right, I haven't gotten my requisite amount of Mountain Dew yet this morning.

I let my HTPC handle all the processing because it's just easier, for me at least. I've gotten the DTS-MA and TrueHD lights on my 609 to light up before, and it was a small victory for my soul, but it wasn't as if I could tell the difference between the 609 and the PC encoding the audio.

You can use Windows Control Panel / Sounds to see what Windows thinks the device supports. You can also test the output there.

You may have to update drivers.

here is a fix that worked for me I am running windows 7.
I have a denon avr-1912 connected through HDMI from my ATI HD 5xxx series.

1) I uninstalled my onboard audio drivers first.
2) Then i went to the BIOS and completely turned off the onboard audio. (so windows doesn't try to reinstall the drivers)
3) Then I uninstalled the AMD catalyst drivers completely.
4) Then I went to AMD's website and downloaded the latest AMD catalyst drivers 12.6 and reinstalled them.

I have switched between inputs several times after this and mine still works.

Also for those who were restarting the computer to get the audio to work again I found that to work, but I just turned the receiver off and turned it back on and it seems to be a quicker solution to bring the audio back on. (I did that until i figured out my permanent solution)

I hope this helps.

My guess is that when you first install the AMD driver initially and you have your onboard audio drivers installed Windows seems to get confused on which driver to pick as the main audio source.