Welding MIC (microphone) buzzer wire harness Steps:
　　 1. Check the MIC: select the good solder joints and the sound insulation fabric at the bottom of the MIC for use.
　　2. Tinning: Use 0.8mm tin wire to tin the two soldering points of the MIC. Note that the solder joints cannot short-circuit the two solder joints with each other, and cannot short-circuit with the MIC shell.
　　3. Soldering the MIC connection line: Weld the connection line from the right to the left direction (see picture), and solder the connection line to the two solder joints of the MIC respectively.
　　4. Self-inspection:
The solder joints are round and full, no short-circuit phenomenon, no false soldering, false soldering, and no sharpening of the solder joints. The positive and negative connecting wires of the MIC cannot be interchanged, and must be consistent with the model;
There are no air leaks in the solder joints.