No HDMI Audio Signal

Hi

I've just recently had to rebuild my HTPC with a newer version of Windows 7. I have been using an ATi HD5450 card in my setup for over a year now with no problems.

However, with this new build I've put on, I am now not getting any signal to my receiver from my HTPC. However, as soon as I turn on my TV, I get a signal to the receiver!! So I can get audio but always have to have the TV on, which is not how I remember it working before.

I am no nearer to finding out why all of a sudden there is no signal from my PC to receiver. I have carried out a few tests that Yamaha have advised me to as I thought the issue was with the receiver but it looks like a problem with the Windows 7 and codecs.

I've just checked and I am running the latest drivers for my card as well.

Hope someone can help! Thanks

Hi
Yes, HDMI is set on the PC. It is the default.
Just tried to install the ATI High Definition Audio Driver and the device failed to start!
I've set it back to the Microsoft one now. Not sure if this is the issue.