LG KU730 Service Manual page 115

4. TROUBLE SHOOTING
4.17.5 Microphone for Head_Set
MIC for Head_Set path as below:
Insert Headset -> EAR_SENSE_N(pin6) go 0V -> MSM6275 sense Head_Set insertion ->
MIC signal go to MSM(C619, C620)
R300
2.2K
R301 10K
CN300
13
15 R302 2.2K
17
1
2
3
R303 51 C300
4
5 R304 51
6
7
8
9
10
11
12
2012
14
16
18
C-1827541
VREG_MSMP_2.7V
MICBIAS
MIC2P
MIC2N
33u
HPH_L
C301 33u
HPH_R
EAR_SENSE_N
MULTI_ADC
HOOK_SENSE_N
2012
Start
Make a call
Try change the head set
NO
EAR_SENSE_N is 0V?
Yes
MIC_BIAS is 1.8V ?
Yes
Change the Main B'd
OK
END
NO
Change headset or
main board.
NO
Change the Main B'd
- 116 -
F25
SDCC_DAT1_GPIO99
M25
SDCC_DAT2_GPIO100
M26
SDCC_DAT3_GPIO101
AE3
MDP_VSYNC_SECONDA_GPIO104
AD2
MDP_VSYNC_PRIMARY_GPIO105
C60
0.1
10%