Connect the X-box 360 with the X-box- HD component cable to EXT 3 of the TV Red Green and Blue cinch connections (the yellow cinch connector is not connected).
Connect the audio separately, with the red and white cinch connectors for audio on the HD cable to the analogue audio input which is a mini-jack connection for EXT3 of the TV or the optical out from the Xbox (via a converter) to the digital coaxial input of the TV.
You may need to re-assign the audio on the TV to the correct connection :
Select TV MENU and press cursor right. The TV menu appears on screen.
Select INSTALLATION and press cursor right. The installation menu is moved to the left.
Select CONNECTIONS and press cursor right. The connections menu is moved to the left.
Select L/R and press cursor right. Select NONE
Select DIGITAL AUDIO IN and press cursor right. Select EXT 3.