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4. TROUBLE SHOOTING
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Copyright © 2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
20
6L
F
12
02
91
12
81
01
16
13
8
9
7
6
11
5
4
14
3
15
2
1
17
UMTS1
UMTS3
GSM1800/1900RX1
ANT
GSM1800/1900RX2
GND1
GND2
GSM850RX1
3
C
V
2
X
R0
58
M
S
G
1
XT
00
91/
00
81
M
S
G
1
C
V
XT
00
9/
05
8
M
S
G
VDD
GND3
2
C
V
4
D
N
G
VC4
2
ST
M
U
5
D
N
G
D
N
G
P
p0
81
81
2
C
SW200
4
2
1
3
1
G
A
C
2
G
100n
L202
4.7K
R129
TRX_W2100
TRX_W900
TRX_AWS
TP2
͑
ͽͶ͑ ͺΟΥΖΣΟΒΝ͑ ΆΤΖ͑ ΟΝΪ͑
͑
FIG 27 Schematic of the FEM
FIG 28 Schematic of the WCDMA I, VIII Rx Path
FIG 29 Schematic of the WCDMA IV Rx Path
TP1
TP2
TP3
TP2
͑
ͽͶ͑ ͺΟΥΖΣΟΒΝ͑ ΆΤΖ͑ ΟΝΪ͑
͑
4.6 WCDMA Receiver Block
GSM Receiver stage is configuring of both FEM stage and MDM RF Receiver.
So, we need to just consider FEM operating and matching components.
Set the Phone Rx to be on
Check TP2, TP3
Signal exist?
Check FEM Block
yes
no
Change the board
Check TP1
Signal exist?
Check RF Switch (M/S)
no
yes
Set the Phone Rx to be on
Check TP2, TP3
Signal exist?
Check FEM Block
yes
no
Change the board
Check TP1
Signal exist?
Check RF Switch (M/S)
no
yes
Chart 5 WCDMA Receiver Block sequence
FIG 26 WCDMA Rx Block
TP 1
TP 3
{wGYG