In sony ericsson c702 mobile some time mic does not work so there no voice to caller’s end.
This problem occurs due to physical problem like water damage or physical shock on mobile.
For solving mic problem apply following solution step by step:
1. First change new mic then problem might be solved.
2. If still no solution then check track continuity from both mic point to mic resistance shown in image below
3. First check track continuity from resistance L3101 shown in blue mark to mic’s positive point if there some problem in track then apply jumper as shown in image using blue line.
4. Second check second track continuity from resistance L3100 shown in red mark to mic ‘s negative point if continuity missing there then apply jumper as shown with red line.
Now after all above tips and jumper setting mic will work properly without any problem.
Jumper setting is last solution for mic problem. Because in Sony ericsson new generation mobile mic IC is inbuilt in CPU IC which is not changeable because it is shielded.