Computer / Headset jack problem.

Hello guys.
I bought a new headset a few hours ago. I just came back home , and immediatly opened youtube to test them. At first they didn't work because of course my computer was downloading some drivers and etc , but when it was ready I played a song. At first I couldn't hear anything. Checked the sound of the headphones , computer's sound but everything seemed to be fine. 5 minutes later of trying to fix them I succeeded. The first problem came. My sound was like bass boosted. (you know the bass boosted songs where your house just falls down because the sound just makes the walls fall.) I checked my Enchantments - Equalizer , but my bass settings weren't on. I just said whatever , they work fine , in the time I will be okay with that. The second problem came. I plugged in the microphone jack too. I went to skype but the real problem because I made this post came. I called echo (the girl with the sound and the voice , you know , where you test your microphone) , but I had no sound again. I saw in my down right corner that something is plugging and unplugging off. It was my sound jack. Tested the microphone with some pauses between the voice (that's my biggest problem :/) , but the microphone seemed fine. So the problem is , my computer jack. When my sound and microphone jacs are plugged in they do some problems. The microphone works fine , but the sound isn't , like I have sound for 2 seconds , then I don't have for 2 seconds , and like that until unlimited space. I plugged both of the jacks in the back of my computer and they worked fine, How can I fix / repair my front jack? (talking about the green one , for the sound) (P.S when I only have plugged the green jack the sound is fine (again with some bass boosted , but fine) , but when I plug the microphone jack the problem comes.) Please halp.