HDMI audio problem (GTX 560M)

I'm having a problem getting HDMI audio from my laptop. The laptop is a Clevo P151HM1 with a GeForce GTX 560M GPU.

When I connect the system to my Onkyo TX-NR708 receiver, the video switches to my TV just fine, but the audio doesn't. Windows reports that the Nvidia HD Audio device isn't connected and I cannot switch to it. The only way to get HDMI audio to work is if I completely shut down my laptop, hook everything up, then boot it up. The audio device is then detected and audio is passed through HDMI. If I disconnect it and reconnect it will again not detect the HDMI audio.

I've tried about every permutation of connection - powerup sequence I can think of, and the HDMI audio never works unless I do the total reboot method which is inconvenient.

Has anyone else had this problem or know of a fix? I have the newest available GeForce drivers installed from Nvidia's website.

Specs:

Intel Core i7
8 GB DDR3 RAM
GeForce GTX 560M
Windows 7 Ultimate 64-bit

 

The only thing I can think of is trying a clean install with the Nvidia and possibly Realtek drivers. Do you notice if this happens with any other HDMI display, or is it only your receiver?

 

I tried it with both my receiver and hooking directly to my TV and it does the same thing.

 

Is "NVIDIA High definition Audio" enabled under "Sound, video, and game controllers" in Device Manager?

 

Yes, and under Output Devices in audio options it says Enabled, not connected.

 

Update: I discovered that if I connect the laptop using the DVI connection with a DVI->HDMI adapter it works and switches to NVIDIA Audio. The HDMI connection still doesn't get detected as connected for Audio unless I reboot the laptop.

 

HDMI Should be hot swappable, but we've had other customers with this issue as well. They have had to shut down, plug the display in, and then boot up in order for it to function properly.

This is odd. It could simply be a power allocation issue for mobile graphics. HDMI has a 5v power line, and this may be what is causing the issue.

Any thoughts?

 

All I know is that my 6990M does audio and video through HDMI flawlessly. I'm hot-swapping it too.

 

I suspect it must be a handshaking issue with the HDMI port. As I said earlier HDMI video always works, its getting the audio function to be detected that's the problem.