When I plug in my headphone, the speaker still sounds, how to solve this problem please, I can use alsamixer to adjust the total volume, but I just want the speaker stopped making sound after I plug in my headphone...Thanks for helping...:-)
Not sure if it's any help, but I had a similar problem with my old tablet pc.
Turned out that the main speakers and the headphones were on different channels. I eventually realised when I took a look at the user options/settings for the mixer and found (and enabled) a couple of extra sliders. So now I've muted the channel for the main speakers, turned the headphones to full and I use the master volume slider to control the overall volume.
So you might want to look into the possibility that your headphones and speakers are on different channels!