I have a HP Pavilion computer and I use Windows XP. It has been hooked up to Sony Vaio speakers for about three years now, and everything worked fine until a few days ago when the speakers stopped working. I bought a new set of speakers and hooked them up and they don't work either. When I first insert the plug into the speaker port on the sound card, I do hear a crackle noise in the speakers, but then nothing. Once the cord is fully plugged in, I cannot get it to make that crackle noise again; it only happens when it's plugged in about 2/3 of the way into the port. The green light is lit indicating that the speakers are on and I have them turned up all the way and have experimented with different volumes - nothing. I cannot get sound on youtube, itunes, computer games, and other online & offline content. I just tried cleaning everything thoroughly with a can on compressed gas/air and it still doesn't work. Any help would be greatly appreciated.