Macbook Air no sound from internal speaker
I Recently found that my MVA losts its sound. When I start up the MBA, it has the chrome sound. But afterwards, it remains slient. The speaker logo on the menu bar doesn't grey and is adjustable. However, when go to system preference>sound, there is only headphone available. When go to audio-midi setup in utility, there is option for the speakers. I really don't know how to fix. I have
reset pram
reset smc
and even reinstall osx to yosemite 10.10.2
I am using Macbook Air 2014
1.4 GHz i5
4GB ram
please help!