Only For Training And Service Purposes - LG GU280 Service Manual

4. TROUBLE SHOOTING
WCDMA Tx Path Circuit Diagram
L116 DNI FL101 B7686
C149 DNI
6 3
WCDMA_1900 ANT TX_IN
1
1
RX_OUT1
C127 8
RX_OUT2
DNI 4
GND1
2 5 2
GND2 GND4
9 7
GND3 GND5
WCDMA_1900
1880,1960MHz
2
C126
C134 2.2p
WLNA_HB1_IN_M
1
L121
L118
10n
DNI
2
C138 2.2p
WLNA_HB1_IN_P
2
C123
B7696
FL106
L120 4.7p C144 3.3n
1 6 3
WCDMA_2100 ANT TX_IN
2
1
RX_OUT1
L119
8
RX_OUT2
DNI
2
GND1
4 7
WCDMA_2100 GND2 GND4
5 9
GND3 GND5
1950 MHz,2140 MHz
C116 1.8n
1
WLNA_HB2_IN_M
2
1
1
L115 L117
1p DNI
2 2
C142 1.8n
1
WLNA_HB2_IN_P
2
FL103 B7671
R111 6.8n
C148 8.2p
1 6 3
WCDMA_LB ANT TX_IN
2
1
C160 RX_OUT1
8
12n
RX_OUT2
2
GND1
4 7
GND2 GND4
5 9
GND3 GND5
836.5 MHz,881.5 MHz
WCDMA_850/900
L108 33p
WLNA_LB_IN_M
1
L107 C124
10n 0.5p
2
L109 33p
WLNA_LB_IN_P
TP8
LGE Internal Use Only
ANTENNA_PAD
ANT102 ANT101
ANTENNA_PAD
RF-800
SW101
C163 C175
0 15p
R110
1n
C104
C105
1p 10n
VREG_MSMP_2.6V
TP5
0
1 PCS_IN_M
DNI C133
+VPWR
2 2
1
C173
C151 C158
DNI
2.2u 330p
2 1 1
TP7
C128 1n
1
DNI C129
2
1 1
C135 C159
DNI DNI
0
1
1 PCS_IN_P
C143
2 2
33p
2
L123 DNI
1 1
C132 C180
DNI DNI
2 2
R109
PWR_DET 2
1
68
TP6
TP9
FL105
C110 33p
2
G2
ANT
ANT RF
G1
L101
1
GND1
100n
8
GND2 GSM850_RX_EGSM_RX2
10
GND3 GSM850_RX_EGSM_RX1
12
GND4
13
GND5
23
GND6
24
GND7
L106
15n
C122
33p
ANT_SEL[0]
ANT_SEL[1]
ANT_SEL[2]
ANT_SEL[3]
+VPWR
2 2
C147 C130
330p 2.2u
1 1
ACPM-5201 U102
11
PGND
10 1
C119
VCC2 VCC1
9 2
1
RFOUT RFIN
R103
8 3
1
2 ISO VBP PA_R1
49.9
7 4
GND VMODE
PA_R0
6 5
CPL VEN 2 2 L125
C140 C155 DNI
1n 1n
1 1
WCDMA_PA_ON0
2
C139
1n
1
+VPWR +VPWR
2
2
C145
C146
680p
680p
1
1
VCC2 VCC1
6 5
RFOUT RFIN
7 4
ISO VBP
8 3
GND VMODE PA_R0
9 2
2
CPL VEN
10 1 C137
PGND
11
DNI
ACPM-5305 U104
1 1
WCDMA_PA_ON1
2
C136
DNI
1
- 54 - Copyright © 2009 LG Electronics. Inc. All right reserved.
85090019002100
17
PCN_RX2
16
PCN_RX1
19
PCS_RX2
18
PCS_RX1
15
14
21
WCDMA_850
22
WCDMA_1900
20
WCDMA_2100
11
GSM850_EGSM_TX
9
PCN_PCS_TX
TP3
FL104 B9414
C118 2.7n
1.5n
4 1
1
OUT IN
2 2
G3 G2 G1
5 3 2
2
1 1950MHz
C150
L122
C141
4.7n
0.5p
DNI
1
2
FL102 B9425
L110 DNI
4 1
OUT IN
G3 G2 G1
2
5 3 2
L111 836.5MHz 1
DNI
PA_R1
1
2
2
C156
DNI
TP4

Only for training and service purposes

TP1
WCDMA_1900
C181 DNI
WCDMA_1900_TX_OUT
C117 33p
WCDMA_2100_TX_OUT
WCDMA_2100
C125 DNI
WCDMA_900_TX_OUT
WCDMA_850/900
L124
DNI
TP2