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Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
4. TROUBLE SHOOTING
MIC for Head_Set path as below:
Insert Headset
Æ
Interrupt which are the signal of Headset detecting arise in EAR_SENSE
Æ
MIC BIAS LDO
U500’s
R506(RES) :1.6V~1.8V(MIC BIAS)
Æ
MIC signal
Æ
FB504
Æ
C204->MSM7227
Insert Headset
& Make a call
Check the TP2 or
Change the Main b’d
TP1 is 1.6~1.8V ?
YES
NO
4. Trouble Shooting
(BB)
4.13.5 Microphone for headset
Can you scoping some
sound signal at TP4?
Check the 3.5pi Ear-jack
Or Change Ear/mic SET
YES
YES
make some sound or
voice to MIC
Work well?
END
YES
Can you scoping some
sound signal at TP3?
Check TP3
Or Change the Main b’d
NO
NO
YES
Start
143P
1
R
2.2K
U500
5
3
2
4
1
VOUT
VDD
GND
CE
D
N
G
P
1800
FB504
2.2u
40
5
C
VREG_MSMP_2.6V
2
R
1K
4.7u
C503
EAR_SENSE
HOOK_ADC
HOOK_ADC|EAR_MICP
EAR_MICP
HS_MIC_BIAS_EN
8
F
8
E
7
F
7
E
7
C
7
B
6
C
5
C
6
B
5
B
P
I
_
R
_
E
N
I
L
N
I
_
R
_
E
N
I
L
P
I
_
L
_
E
N
I
L
N
I
_
L
_
E
N
I
L
P
1
C
I
M
N
1
C
I
M
P
2
C
I
M
N
2
C
I
M
P
I
X
U
A
N
I
X
U
A
u1
20
2
C
u1.
0
30
2
C
u1.
0
40
2
C
50
2
C
u1.
0
u1.
0
70
2
C
u1
80
2
C
33p
C7
39p
C223
MIC_VGND|GND
D
N
G
V
_
C
I
M
R_
OI
D
U
A_
MF
L_
OI
D
U
A_
MF
P
CI
M_
R
A
E
P_
CI
M
TP
TP1
TP2
TP4