No sound through DisplayPort

I'm trying to connect my Elitebook 8440p laptop to my Samsung HDTV. The laptop does not have a HDMI connection, but it does have DisplayPort. I bought a C&E TOOGOO DisplayPort-to-HDMI adapter, and connected it with a 3 feet HDMI cable. The video shows up fine, but there is no audio. DisplayPort, HDMI, and the adapter all support audio.

I contacted HP tech support, who told me to update my sound drivers. I installed the driver and rebooted. Supposedly, I should see a "HD Audio" tab. No luck, even after installing the driver again and rebooting. HP closed the case. I'm using Windows XP Pro.

I travel a lot – here is what I do:

• plug in HDMI
• turn on TV to right input etc...
• close the lid and let it go to sleep wait a few seconds
• open the lid then quickly close it
• wait for it to output video to the TV (you may need to reboot with lid closed)
• then open the lid if you need to setup screens etc.. I found the intel software left in clone mode works great! My res is 1280x720

I use a display port to HDMI dongle but it should not matter.

I ran across this same issue recently with my Dell Latitude running an Nvidia NVS3100 mobile graphics card, using a similar adapter to a 24" HDMI Dell monitor and from researching, I found that Audio is an optional signal with Displayport 1.1a. Most hardware these days is enabled, but updated drivers are a must, which is why the support told you that. Quite rude to shut you down without giving you a link to the driver, however.

The HP forum thread below may have a solution for you, as they're using similar setups and have found working solutions. I don't have an actual solution here, I'm merely trying to be of use as I struggled to get my issue resolved recently and I know what a pain in the butt it can be!

Sources:

1. Displayport FAQs

2. HP forum

Edit:

I also just found these tips that might work for you:

On a machine with a discrete graphic card - just choose NVidia HD audio as playback device after connecting your display. On a machine with an integrated graphic card - the trick is to go to Control Panel > Sound control panel > Right click on your TV > Select 'Set as Default Device'. Then you should start hearing audio out from the TV speakers, and the green sound volume meter beside the TV in the Sound Control Panel should start responding to the audio you're playing.