Windows 7: Netbook to TV (via HDMI cable) - no sound on TV.

I have a Netbook that I connect to my TV (via an HDMI cable), and use to watch videos/movies/tv shows. The netbook was working fine ... then I installed a windows update, rebooted, and the sound doesn't work when plugged into the TV anymore.

The exact computer I have is the HP dm1z ...
HP Pavilion dm1 and dm1z series | HP® Official Store

I checked some of the threads and ran through some basic troubleshooting...

First, I checked the computer audio. It is NOT set to MUTE. And the volume is at 100%. I also checked the TV volume, which is set to a regular level (I even switched to "regular TV" and the sound worked fine).



I've checked the Playback Devices (See attached image aud1.jpg). It shows that the ATI HDMI Output is connected and set as the default device ... but when I TEST the device, no sound is played. To test, I checked to see if ANY sound would play. I tried opening videos, sound files and checking the windows default sounds (see aud2.jpg). None of those played with the ATI HDMI Output selected.

So, I tried to change the default device to "Speakers and Headphones" (see aud3.jpg). This made the sound play on the laptop, but not on the TV (so, sound does work... it's just not sending it to the TV). Then I switched the default device back to "ATI HDMI Output" so I could troubleshoot further.

I checked the Device Manager, and all of the sound drivers are working, and up-to-date. No issues there.

This WAS working this morning, but now it is now. So, I tried to restore the system to an earlier date ... the system restore did not work. The sound still isn't playing on the TV.

So, I thought maybe something happened to the HDMI Cable. So, I tried to switch with a different cable. Neither HDMI Cable worked. Then I tried to connect the cable to a differ HDMI port on the TV (thinking maybe the port on the TV was busted) ... but that didn't work either.

At this point, I'm running out of options. I'm not very technical ... so any help is appreciated (please keep things in simple terms, thanks).

D.