you dont mention the model of your laptop. is the onboard sound realtek HD? and are you using windows 7 or vista? If so you can give this a try. enter control panel then click on hardware & sound. you will see the realtek HD audio manager icon. click on that. then double click on the two jack icons below "analogue" and you'll get a choice of headphone or line out. select the headphone option. this might solve the problem. otherwise you can try downloading and installing the latest driver from realtek.