lutusp - tried it and didnt make a difference.
Ok i have reinstalled the OS again from a fresh and the sound has worked. Sound worked through the TV as I wanted it.
I saved the asalmixer settings using the following command
And rebooted. The PC came back up again with sound with all the cabling still plumbed into the TV. Great.
I then removed the 3.5mm sound jack when performing a sound test. Inserted the jack and sound could be heard through the TV. Great.
Decided not to perform any widespread software updates but installed the nvidia graphics 180 version. Installed and rebooted.
Sound dead through the TV – works via headphones.
Rebooted – still no sound.
Uninstalled nvidia drivers and rebooted. Sound has come back.
Installed nvidia version 173.....no sound. Removed them and sound has returned.
So the graphics card drivers are influencing the sound.
Incidentally I have a spdif connection in the back of the PC going to the TV also.