Hi. I just bought a new HP Slimline 260a010 desktop. The only issue is I cannot get sound working through external speakers. I tried two different sets of speakers, both know to work on other computers (desktop and laptop). I ran the troubleshooter and it did not help. I am plugging into the stereo 1/8" jack (green) in the rear of the computer. What is confusing is that when I plug my headphones into the same jack in the back I get sound. Please advise what I can try next.