Sidetone Not Transmitted (Earpiece ); Sidetone Not Transmitted (Hands Free Mic ) - Pantech G310 Service Manual

G310 Service Manual
6.2.3 Side Tone Not transmitted ( Ear-piece )
Repeat 6-2-1 No receiving tone heard.( Ear-piece )
1. Check to see if Mic + pin is around 1.8V : CP125
NO Check that R102, C181 and R104 is cold solder, broken, short to the other
PCB pattern or not
If you find out any defective part, you replace it.
Set to HP8922M to connect a call and then set to 1kHz with Echo audio mode.
2. Check U102.J10 (C132) pins for wave form : CP126
NO Replace MIC
6.2.4 Side Tone Not transmitted ( Hands-free Mic. )
Repeat 6-2-2 No receiving tone heard.( Hands-free Earphone ).
1. Check to see if U102. H10 (C130) pin is 2.5V : CP127
NO Check that R107, R108, C150 and C151 is cold solder,broken,short to the other
PCB pattern or not.
If you find out any defective part, you replace it.
Set to HP8922M to connect a call and then set to 1kHz with Echo audio mode.
3. Check U102. H10 (C130) pins for wave form : CP127
NO Replace Handsfree Mic.
CP126
CP127
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PANTECH
CP125
R&D CONFIDENTIAL
CP125