TCL T728 Service Manual
TCL Mobile Communication
CO., Ltd
第
29
页
共
32
页
Circuit of backlight for LCD
5.5 NO transmitting
1
、
Trouble
：
In normal idle mode, dialing 112, can hear the voice from network, but there is
not any sound while scratching the Microphone.
2
、
Analysis: after the audio signal is transferred into electronic signal, it is directly sent to
CPU for process. At last it is sent to earpiece. If there is no transmitting, should check
this part carefully.
3
、
Maintaining steps
：
3
．
1 Using the multimeter to measure the value of the resistance of the Microphone. The value of
the positive resistance is about 1K ohm, while the other is around 700 ohm
；
3
．
2 Taking off the Mic, judging if the MT6205 can work well by the way of measuring the
value of the resistance between the exploded two points on the mainboard.
文件使用
"pdfFactory Pro"
试用版本创建
