Acer Travelmate 2310 Microphone problem

[emachinese625]

Hi. My friend has an problem in his acer TravelMate 2310. It has an build-in intergrated microphone, and when we talked in skype and ended the call, then he comed back and called me, and then his mic not working anymore.. How to turn mic back to on? We dont find nothing to enable mic from eManager, and nothing found from Sound Effect manager. How to turn it back on?

 

[emachinese625]

And sound card is Realtek AC97