Nokia asha 311 Mic problem solution

Now I showing how to find Nokia asha 311 mic problem and how to solve it.At first check your phone calling by other phone.when you conform your phone is mic problem then open phone.next view below picture.

How to do this : Clean full pcb and hit with lamp then call this phone and see result.If problem still then first check red mark parts.then check mic , this is four leg mic.If you see mic is damage then change mic.