Lte Tx Trouble - LG FM300 Service Manual

4.12 LTE Tx Trouble

4.12 LTE Tx Trouble
1732.5 MHz,2132.5 MHz
SW100
FL101
G1 C101 18p L103 47p
47p
C100
6
ANT
G2 ANT
2
GND1
R102 C102
4
GND2
27n 4.7n
5
GND3
TP3 TP3
U101 SKY77704-18
C152 47p
TP3
CPL_OUT CPL_OUT VEN
6 5
GND VMODE_0
C150 47p
7 4
CPL_IN VMODE_1
C112 8.2p C151 15p
8 3
RFOUT RFIN
9 2
VCC2 VCC1
10 1
PGND
11
L112 R112 R119
49.9
10n 12n
C124 C125 C126 C127
680p DNI 10u 10u
TP3
TP7
U101
U102
TP2
TP5
LGE Internal Use Only
698M 960M
FL106 HHM1726T4
B7959 L115
1 3
RX1
B2
8 8.2n
1
RX2
UB
4
B1
C141 C142
3
TX
1p DNI
7
C143
L116
GND4
9 DNI
GND6
8.2n
TP6
TP7
SYS_PWR
R105
0
TP6
PA_EN1
842MHz
FL104
PA_MODE0
SAFEA842MAL0F00
PA_MODE1
C113 47p
1
IN OUT
G1 G2 G3
TP7
C117 R109 C118 C119 2 3 5
L113
R113
18n
1n 4.7K 1n 1n DNI
C128
680p
TP1
4. TROUBLE SHOOTING
LNA0_MODE1
U100 BGA751L7
L117
1
RFIN RFOUT
4.7n
2
VEN RREF
L104
10n
3
C144
VGS VCC
2.2p
C105
C106 C107
100p
1n 1n
TP2 TP2
R108
DNI
U102 SKY77704-18
C153 47p
TP2 CPL_OUT VEN
6
GND VMODE_0
C154 47p
7
CPL_IN VMODE_1
C114 47p
4
8
RFOUT RFIN
9
VCC2 VCC1
10
PGND
L114 11
R116
R120 R121
12n
18n
49.9 49.9
C129 C130 C131 C132
330p 10n 2.2u 10n
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4. TROUBLE SHOOTING
2V8_LNA
R100
0
2 3
L102
47p
C104 FL109
G1 O1
6 1
IN SAFEA806MCL0F00
3.3n G2 O2
806MHz
R103 5.6k
5 5 4
4
TP4 C108 C109 C110
10n 100n DNI TP1 TP1
TP5
SYS_PWR
TP4
R106
R107
0
DNI 698M960M
FL103
PA_EN1 TP1
5 HHM1726T4
4
C115 6.8p C116 47p B2
3 1
UB
2
B1
1
C120 R110 C121 C122
TP5
R117
R118
27n
1n 4.7K 1n 1n DNI
C133
2.2u
TP6
Only for training and service purposes
L105 4.7n
RRFM1_INN
L101
R101
5.6n DNI
L100
RRFM1_INP
4.7n
C111
TRF1_OUTP
1n
3
L106 L107
DNI
1p
4
C123
TRF1_OUTN
1n
TP4