Hi, ive been using my Astro a40s for 2 years, i bought a soundcard with them because the use anoptical output cable. Today i noticed that the optical port in the soundcard was dark an i think that it should, and also have been lit up. then i turned on the computer and listened to music and i puuled ot the cable and nothing happened. It makes no difference in sound if the cable is in or not. Is there a small difference? Should the port be lit up?