Logitech Z906 optical port no sound

[marcus.lexander]

I just got a brand new set of logitech Z906 after returning my old ones after a buzzing sound, now these new ones are fine... except that I can not play any audio at all with the optical ports (3, 4). I tried plugging the audio system to my TV, Xbox 360 and PC using all ports and I get no sound at all when testing.

I want to try the cable on another set of speakers to verify it's only the cable because I really don't want to have to go through another return.

 

[nitinvaid20]

so the old one was also? Z906 they are working on Optical ?