Side Tone Not Transmitted (Hands-Free Mic) - Pantech PG-1810 Service Manual

PG-1810 Service Manual
6.2.6 Side Tone Not transmitted ( Hands-free Mic )
Repeat 6-2-2 No receiving tone heard.( Hands-free Earphone ).
1. Check that if R223 and C252 pin's voltage is around 1.77V when the hands-set is connected:
CP127 ( If the hands-set is not connected that Voltage is around 0V. )
NO Check to see U202.N16 or R223, C252 cold solder, broken, short to the other
PCB pattern or not.
If you find out any defective part, you replace it.
Set to HP8960 to connect a call and tell to Hands-free mic.
2. Check to seeL201 and S213 pins for wave form : CP128
NO Check that U201 or L201 are cold solder, broken, short to the other PCB pattern or not
or Replace MIC
If you find out any defective part, you replace it.
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PANTECH
CP127
CP128
CP128
CP127
R&D CONFIDENTIAL