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SGH-S400i Flow Chart of Troubleshooting
2-
32
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R101
C101
C132
C102
C141
C113
C110
C124
R13
C122
R19
VPAC_2.8V
ANT1
VRF_2.9V
R16
R113
VSYN_2.8V
C107
C182
C108
C116
C111
C183
R110
CAP_I-
9
EDGE_REF-
6
D
N
G
0
6
D
N
G
1
6
D
N
G
2
6
D
N
G
3
6
D
N
G
4
6
B
B_
XI
M
_2
C
C
V
7
CAP_I+
8
LO+
52
LO-
53
RX_I+
54
C
N
5
5
BANDSEL
56
BS2
57
TX_I+
58
D
N
G
9
5
TX_I-
45
TX_Q-
46
D
N
G
7
4
CAP_Q+
48
C
N
9
4
E
5
SX_EN
50
DATA
51
V
R
D
_
C
C
V
8
3
A
N
L_
C
C
V
9
3
TX_Q+
4
TX_CPO
40
EDGE_LO
41
LNA900
42
LNA1800
43
D
N
G
4
4
RX_I-
30
B
B
_
C
C
V
1
3
O
C
V
_
X
T_
C
C
V
2
3
TX_900_OUT
33
TX_1800_OUT
34
TX_TUNE
35
RX_EN
36
TX_EN
37
D
D
V
3
2
UHF_BYP
24
UHF_TUNE
25
F
H
U_
C
C
V
6
2
O
L_
C
C
V
7
2
RX_Q-
28
RX_Q+
29
3
P
F_
C
C
V
6
1
SYN_REF
17
UHF_CPO
18
N
F
_
C
C
V
9
1
EDGE_IF-
2
XTAL_TUNE
20
CLK
21
LE
22
LNA1900
1
CAP_Q-
10
26MHZ_PAD
11
LPF_ADJ
12
CLK_BUFF_OUT
13
D
N
G
4
1
D
C
C
V
5
1
UPL101
C119
VCCD_2.9V
L103
G
8
G G
910
G G
1214
G G
18
PCSRX 11
19
G
2021
G G
2223
G G
24
3
G
5
G
7
DUF100
ANT
6
13
DCSRX
1
G
G
C114
ANT_GND
L104
C115
C120
C103
C131
C185
7
01
L
C130
R149
C109
L102
C133
L101
C123
1
G
4
G
R112
RFS100
A
2
3
C
L105
C112
IF_OUT-
SERCLK
SERLE
LO
SERDAT
BAND_SEL
IF_REF-
GSM_OUT
DPCS_OUT
DCS_TX_EN
GSM_TX_EN
TRXQP
TRXIP
RX_EN
GSM74945_OUT
TRXIN
TRXQN
CLK13M_RF
SX_EN
TX_EN
DCS74945_OUT
ANT
(0603)
(0603)
(0603)
(0603)
C178
C127
C136
C117
C137
C184
C128
C138
VRF_2.9V
C126
C135
R114
V_IF1
29
2
FI
_
V
V_RF 21
VBAT
LO_IN
33
C
N
PAC_EN
45
30
C
P
A
V
35
T
A
B
V
47
VCCA
1
B
C
C
V
C
P
V
41
23
9
D
N
G
53 GSM_IN
T
U
O
_
M
S
G
15
31
+
NI
_
FI
32
-
NI
_
FI
24
25
IF_OUT-
27
LE
22
GND32
GND33
56
GND
57
4
D
N
G
5
6
5
D
N
G
7
6
D
N
G
8
7
D
N
G
9
8
D
N
G
10
52
D
N
G
44 GND26
GND27
48
49
GND28
GND29
50
4
3
D
N
G
GND30
52
GND31
54
55
81
D
N
G
36
91
D
N
G
2
D
N
G
3
37
02
D
N
G
38
12
D
N
G
39
22
D
N
G
40
32
D
N
G
42
42
D
N
G
43
0
1
D
N
G
11 12
1
1
D
N
G
2
1
D
N
G
13 14
3
1
D
N
G
GND14
16
17
GND15
18
GND16
20
GND17
34
BANDSEL
46
28
CLK
26
DATA
51
DCS_IN
19
DCS_OUT
1
D
N
G
2
PAM102
C118
R111
L106
VRF_2.9V
C121
92
1
C
PAC_EN
SERLE
IF_OUT-
-
F
E
R
_
FI
+
F
E
R
_
FI
GSM74945_OUT
DCS74945_OUT
SERDAT
SERCLK
BAND_SEL
LO
GSM_OUT
DPCS_OUT
VAPC