Samsung GT-M200 Mic Problem Jumper Solution
https://gsmfixer.blogspot.com/2015/11/samsung-gt-m200-mic-problem-jumper.html
Samsung GT-M200 Mic May Not Working Due to The Water Damage Problem on the mic connectors and there may be fault in the mic itself.
So recommended solution is that you should ensure that there is not water damage and mic is working fine, You can check it with the help of multimeter. After this apply this hardware solution with jumper ways.