4. TROUBLE SHOOTING
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Copyright © 2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
Schematic of the Antenna Switch Block
Antenna Switch Module logic(SKY77584)
ANT_SEL 0
ANT_SEL 1
ANT_SEL 2
Tx_EN
STAND-BY
LOW
LOW
LOW
LOW
GTX_LB
LOW
LOW
HIGH
HIGH
GTX_HB
LOW
HIGH
HIGH
HIGH
GRX_LB
HIGH
LOW
LOW
LOW
GRX_HB
HIGH
HIGH
LOW
LOW
WTRX_HB
HIGH
LOW
HIGH
LOW
WTRX_LB
LOW
HIGH
LOW
LOW
C1118
6.8p
FL1001
4
3
2
1
5
10
6
7
8
9
GSM900_Bal_OUT2
GSM900_Bal_OUT1
GSM850_Bal_OUT2
GSM850_Bal_OUT1
GND5
GND4
GSM850/900_IN
GND1
GND2
GND3
FL1002
4
3
2
1
5
10
6
7
8
9
GSM1900_Bal_OUT2
GSM1900_Bal_OUT1
GSM1800_Bal_OUT2
GSM1800_Bal_OUT1
GND5
GND4
GSM1800/1900_IN
GND1
GND2
GND3
100p
C1046
75
R1006
91
R1007
DNI
C1123
R1008
91
R1013
130
R1011
47
R1012
130
C1126
DNI
39p
C1047
DNI
C1124
8.2n
L1009
C1039
100p
U1001
16
15
14
13
12
11
10
17
9
8
7
6
4
3
28
1
44
43
42
41
40
39
38
37
36
35
32
33
34
24
23
22
29
30
31
18
21
25
20
26
19
27
5
2 GND2
GND5
GND13
TRX1
AN
T
TRX2
GND12
TRX3
VRAMP
PGND3
PGND2
PGND1
GND10
TRX
4
GND11
PGND6
PGND5
PGND4
PGND7 PGND8 PGND9
PGND10
PGND11
PGND12
PGND13
PGND14
PGND15
PGND16
GND1
GND14
GND3
GND4
GND6
GND7
GND8
TX_HB_I
N
TXEN
TX_LB_I
N
BS2 BS1 VBAT
T
VC
C
GND9
MODE
VBAT
R1002
2.2K
DNI
C1125
L1004
4.7n
10u
C1038
C1022 1.2n
GSM_PA_RAMP
ANT_SEL2
ANT_SEL1
ANT_SEL0
W850_W900_RTX
W1900_W2100_RTX
GSM_PA_EN
RX_PCS_M
RX_PCS_P
DCS_PCS_TX
GSM850_GSM900_TX
GSM900(880-915MHz)
2mm
GSM850(824-849MHz)
DCS(1710-1785 MHz)
PCS(1850-1910 MHz)
7dB
11dB
TP1