HDMI no sound

I recently bought a computer and installed an ATI Radeon 4650 graphics card. I use the HDMI connector on the card to connect to my TV. The video works beautifully, but I noticed that sometimes my sound stops working for some reason. I have to unplug the HDMI cable from my computer and plug it back in in order to get the sound to work again. Does anyone know why something like this is happening? This is really annoying since I am using my computer as an HTPC.

Thanks in advance for any help provided.

Check your audio options (Control Panel -> Sound) where you should have SPDIF output enabled.

I am having the same problem with my 4670. I tried everything but the under the Sound Option I do not get the "Ati Hdmi" option.

what options do you get?

Juno1

If your driver installation & bios settings are correct. Using the Device Manager /(Sound, Video & Game Controllers) you should see "ATI High Definition Audio Device."

On the Sound Option at the Control Panel you should see "ATI HDMI Output"

Under "Sound and Audio Devi" i get only the "SigmaTel Audio" only, nothing else

Under "Device Manager --> Sound Video" I can see "ATI HDMI Audio"

I have no idea why. I have reinstalled the drivers from CD and from reltech, same outcome

Sorry, I don't know what CCC is.

But under the "Shouds an Audio Devices Properties" the only option I have is "SigmaTel Audio"

The ATI Radeon 4670 graphics card is the only display.

The ATI Radeon 4670 graphics card is NOT the display. Did you have the HDTV attached when you were looking at CCC?
Also look in Control Panel and see what Display info/properties is there.

http://ati.amd.com/products/catalyst/HDTV_Setup_Guide.pdf

I have the same problem. I have the HIS 4650 AGP, it has a native HDMI and when I try to install the HD audio driver it ask to reboot and then I don't see it anywheres in my system? Anyone else getting this wierd install problem? I don't know what more to do? I'm going to try and boot in safe mode and reinstall the driver. I'll be back to see if this fixed the problem.

Thought I would post in this thread because it seemed like the best match to the problem I'm having. I've got the Radeon 3200 Card, on XP Pro using the M3A78-EMH HDMI Motherboard.

I've got an HDMI connection from my PC to a 32" LCD. The picture works fine, no problem there. And initially, the audio does as well after starting up my computer. However, after switching inputs back and forth from TV and back to PC several times, any streaming video I try play or anything from youtube, I have no sound. I usually remedy this by restarting my computer which gets the sound working again, but invariably I run into the same problem some time after with the sound not working for streaming video or youtube eg.

I looked into the above suggestions and they don't seem to work. Any other ideas?

Thanks.

I recently re-installed my windows 7 due to addition of new memory and having some memory errors. After installation I have noticed that my sound doesn't work through an HDMI with Radeon HD 5770. I remembered that this happened before but I completely forgot how I fixed the problem.
SOLUTION:
Finally my brain woke up and said, check the driver updates for your motherboard. My motherboard has integrated sound card and so there was the problem. I have a Gigabyte 770T AM3 USB3 motherboard and there you go. I don't know if the motherboards with no sound will work, but then again, I don't remember a single motherboard not having the sound card integrated in it. May be back in the old days.
So just update/download your motherboard audio/sound drive from whatever company your motherboard was manufactured at.
Hope I helped.
Val. (AKA The IMPALOR)