Headphones problem

[Erasmus®]

hi guys, need your help with a headphones problems.
I had my macbookpro repaired 3 times and replaced once and still have a problem left: I cannot skype my friends with normal headphones. I mean those which have a green and pink jack: the pink line in jack signal isn't caught by the machine. Am I doing something wrong or is something wrong in the machine? I'm forced to talk on the internal microfone!!! thank you

 

[Sesshi]

The Macs don't have a mic preamp. That's why your friends aren't hearing anything. Buy a USB headset.