microphone is not working

@sharat84711 first make sure that you try your mic while your phone is in safe mode. That would rule out a third party being the problem. The put your phone into safe mode follow the instructions from here

If your mic not works, you will need to remove all previously installed third party apps. Do one at a time until you find the offending app.

If it still does not work, time to replace the mic. The mic is installed to the daughter board. You can either replace the mic be desoldering the old one and solder a new one in it's place. The easiest of course would be to replace the sub_board / daughterboard. Since iFixit does not yet have a specific guide for that, use something like this video to work on your phone and to replace the board.

Should even a new mic not working, try to check something like this video

While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has a device with the same issues as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.

Repair is War on Entropy!