Currently Being ModeratedJan 6, 2013 2:16 AM (in response to Seb1101)
Welcome to the Apple Support Communities
Open System Preferences > Sound > Output and select "Internal Speakers". If you don't see it or it doesn't work, take the Mac to an Apple Store
Currently Being ModeratedJan 6, 2013 2:52 AM (in response to mende1)
Thank you for your answer!
I can clearly see it!
And by the way I just found a way to solve the problem so this subject can be closed!
I putted my headphones in and out until it unlocked the sound volume icon and the red light went off !
I hope this will help other people in the same case !