3. TROUBLE SHOOTING
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Copyright © 2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
Set the phone Rx is On
Check RF Switch (M/S)
No
Yes
Change the board
Check TP1 Signal exist ?
Check TP2 Signal exist ?
Check Tx Module
Refer to 3.4
No
Yes
Schematic of GSM/DCS/PCS Rx Block
L1002
2n
100p
C1001
DNI
L1003
15n
L1005
C1013
1.2n
7.5n
C1028
C1024
1.2n
L1006
DNI
7.5n
C1040
1.2n
C1022
4.7n
L1004
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
DNI
L1007
10p
C1041
10p
C1048
15n
L1008
10n
L1012
8.2n
L1035
8.2n
L1036
DNI
C1005
DNI
L1013
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
8.2n
L1009
2
1
HJ-ICT-06Y
ANT1002
1
DNI
C1004
C1127
1p
C1002
6.8p
C1003
DNI
SW1000
4
3
2
1
ANT
COMMON
G3
G4
100p
C1046
L1001
15n
2
1
C1007
1.8n
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
RX_PCS_P
RX_PCS_M
RX_DCS_P
RX_DCS_M
RX_GSM_900_P
RX_GSM_900_M
RX_GSM_850_P
RX_GSM_850_M
W1900_W2100_RTX
W850_W900_RTX
GSM(925-960 MHz)
DCS(1805-1880 MHz)
PCS(1930-1990 MHz)
GSM(869-894 MHz)
TP2
TP1