LG CU920 - Front-End Module (FEM) Troubleshooting

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4. TROUBLE SHOOTING
4.7 Checking WCDMA Block
4.7.1 Checking Tx level
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Only for training and service purposes
Bottom side
Bottom side
TP1
TP3
TP3
TP2
TP2
TP4
TP4
TP5
TP5
TP6
TP6
TP7
TP7
Fig. 4.7.1.1 Test point of the WCDMA TX Block
WCDMA
B7637
ANT
GND1
GND2
GND3 GND4
GND5
GND6
RX
TX
U103
3.9nH
L134
1000p
C151
L903
4.7nH
7
VEN_PCS
3
VMODE
AWT6321R
5
GND1
GND2
9
10
GND3
GND4
14
15
PGND
RFIN_CELL
2
RFIN_PCS
6
13
RFOUT_CELL
8
RFOUT_PCS
VBATT
4
12
VCC
VCCA
11
1
VEN_CELL
U105
3.3nH
L904
15nH
L128
51
R124
C146
7p
NA
L135
10nH
L127
NA
L131
C165
10p
6
1
O1_CELL
4
O2_PCS
FL103DGLP36M01
G1
2
G2
3
G3
5
G4
10
7
G5
8
G6
I1_CELL
9
I2_PCS
L908
1.5nH
C147
33u
L130
6.8nH
L132
3.3nH
0.01u
C152
C167
NA
68p
C149
8.2p
C154
NA
C159
100p
NA
C930
C150
C933
NA
C144
33p
C168
0.01u
C145
27p
CP0402A1880EL
U104
4
50OHM COUP
3
IN
2
OUT
1
68p
C153
4
50OHM COUP
3
IN
2
OUT
1
CP0402A0836BNTR
U102
G6 G7
RX TX
ACMD-7402-TR1G
FL102
ANT
G1 G2 G3 G4 G5
39p
C148
WCDMA_850_TX_OUT
PA_ON1
PA_R0
PA_ON2
+VPWR
WCDMA_1900
RX_WCDMA_1900
WCDMA_1900_TX_OUT
RX_WCDMA_850
WCDMA_850
HDET
Fig 4.7.1.2 Schematic of the WCDMA TX Block
TP3
TP2
TP5
TP7
TP6
TP1
TP4
SW100
ANT
G1
G2
RF
KMS-512