I just joined to answer the above question, as I saw that people were still struggling with this problem. It was while reading something in the original thread that gave me the insight to dig a little deeper.
My issue was that I connect my laptop to my TV using a USB to HDMI box. All of today I have been playing with software trying to get my integrated webcam to work on my Dell Inspiron 1545, only to find that it was not working owing to a loose cable. But this also became the cause of my sound problem.
I noticed that the drivers for the sound output for my speaker icon for my tv were not correct, mine had a creative .inf as the main driver which could not be right, and seemed to coincide with software that I had installed earlier in the day. I had uninstalled and reinstalled the Viewspan software but this had not worked. So I went to device manager, uninstalled the device from there, and then my system re-installed the correct driver and my sound was back!
Hope that helps someone!
No sound on LCD tv with HDMI cable..Windows 7 - My Soloution
Thank you for your insight into the matter and for finding the fix, definitely this addresses the HDMI issue for many users.
From your post I understand that apart from the sound issues with the HDMI you are facing the problem with the webcam. I would be glad to assist you with this problem. Please let us know if you have got the issue fixed by re-seating the cable? As you mentioned, "...only to find that it was not working owing to a loose cable", I would like to know if the issue still persists.
To know more about Dell's products, services and drivers & downloads, please go to http://dell.to/YBlak6
I tried all types of software downloads before I realised that the camera was reporting as an unrecognised usb device in device manager. I removed the top four screws of the bezel on my Dell Inspiron 1545 removed the small cable and then re-sat it again. When I did this windows found it and installed the camera.