How To Set-up an HDTV
Another note, HDMI cables carry both the audio and video signals. All other cable connections require a separate connection for sound and picture.
The source (cable box, DVD player etc.) will have both audio and video output connections, choose the best and connect those to the inputs on the AV receiver, or if you aren't using a receiver, directly to the TV. If you do have an AV receiver, then will then need to also connect the highest quality output from the receiver to the TV. You only need to make one connection because the AV receiver will switch between the various source components and output through the single connection.
Like video, you will connect audio using the best available connection. Unlike video, there is no need to make audio connections to the TV, unless you are not using an AV receiver. However, even though it isn't necessary, I usually connect the audio to the TV, usually for troubleshooting or unique situations where I want TV sound for some reason.
What If My Home Theater System Doesn't Work?
When setting up a new system, and you don't get audio, video or either, the problem is often in the settings on the TV or AV receiver. You can double check your wiring connections, but the problem is probably in the configuration of the components. The instructions that come with the equipment will explain using the set-up menus to make various settings. Unfortunately, each manufacturer does it their own way. Their way, often isn't intuitive and sometimes it is downright lame.
If I can't figure it out from the instructions, the system I use is to be methodical. I make one single change and then I test it. If it doesn't work, I change it back and change the next setting and I test it. The mistake most people make during this trial and error approach is that they either change more than one thing at a time or they get impatient and skip testing some of the possibilities, often because they don't think those settings could possibly matter. Trust me, as a professional, I have been there. I just keep plugging away, one change at a time and eventually I get it working. Sometimes, it helps to eliminate some of the equipment and work with just two core pieces, like the TV and the DVD player. Once I get two pieces working, I then add the receiver back into the picture. I know the two pieces work and so now I fiddle with the receiver's settings.
If all else fails, start by checking the manufacturers' website. If you are having problem, odds are other people have too and the answer might be posted right there in the FAQ's or product set-up page. Next up try e-mail or telephoning the help desk. I usually try e-mail first, but some companies have good phone support and so it may be worth starting with the phone if it will get you an answer more quickly.
Good Luck - Your Patience Will be Rewarded