LG GU280 Service Manual page 42

Checking Points
TP2
TP3
Logic Table
Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
ANTENNA_PAD
ANT102
TP1
2100/850
GSM850/900 Tx
GSM1800/1900 Tx
WCDMA 850
WCDMA 1900
WCDMA 2100
GSM850 Rx
EGSM Rx
DCS Rx
PCS Rx
Mobile Switch & FEM Circuit Diagram
TP3
ANT101
TP3
ANTENNA_PAD
RF-800
SW101
C163
C175
0 15p
G2
R110
ANT RF
G1
1n
C104
C105
1p 10n
TP1
TP1
VREG_MSMP_2.6V
C122
33p
ANT_SEL[0]
ANT_SEL[1]
ANT_SEL[2]
ANT_SEL[3]
1 1
1 0
0 0
0 1
0 0
0 0
0 1
0 1
0 0
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4. TROUBLE SHOOTING
TP2
TP2
FL105
C110 33p
2
ANT
L101
1
GND1
100n
8
GND2 GSM850_RX_EGSM_RX2
10
GND3 GSM850_RX_EGSM_RX1
12
GND4
13
GND5
23
GND6
24
GND7
GSM850_EGSM_TX
L106
15n
0 0
0 0
1 1
0 1
0 1
1 1
1 0
0 0
0 0
LGE Internal Use Only
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
9
PCN_PCS_TX