Audio Systems: surround sound help!, hdmi cables, yamaha rx

Question
I have an LG tv and am trying to set up a yamaha RX-V665 surround sound system to it.  All of the cords are plugged in, including an HDMI cable going from my cable box to the receiver, and the receiver to the tv.  For a little while the radio sound worked, but now there is no sound at all when we turn on the surround sound no matter what setting it is on.  We get a picture on the tv, just no sound.

I am reading online about HDMI cables...could that be my problem?  I don't know enough about electronics to fix it myself!

Answer
You can try a new HDMI, but that doesn't seem to be the issue, as you're getting a picture. How long of an HDMI cable are you using?

Before you read any outright lies about HDMI and what you may or may not need for your system, I highly recommend looking here for information:

http://bluejeanscable.com/articles/hdmi-cable-information.htm?hdmidept

You'll get no "sales pitch".

From your description, it almost sounds like your receiver is bad. Am I correct in saying you get no sound at all regardless of what input settings you're using (including the radio)? Do you have any other devices you can try with the receiver, such as dvd or CD/MP3 players?

What kind of cable box are you using?

I you can get back to me with this info, I'll be able to get you some better answers / suggestions.
Thanks!