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4. TROUBLE SHOOTING
- 77 -
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
TP1
͑
ͽͶ͑ ͺΟΥΖΣΟΒΝ͑ ΆΤΖ͑ ΟΝΪ͑
͑
4.5 GSM 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 4 GSM Receiver Block sequence
FIG 23 GSM Rx Block
{wGY
{wGZ
{wGX
͑
ͽͶ͑ ͺΟΥΖΣΟΒΝ͑ ΆΤΖ͑ ΟΝΪ͑
͑
4.5 GSM 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 4 GSM Receiver Block sequence
FIG 23 GSM Rx Block
{wGY
{wGZ
{wGX
͑
ͽͶ͑ ͺΟΥΖΣΟΒΝ͑ ΆΤΖ͑ ΟΝΪ͑
͑
FIG 24 Schematic of the FEM
FIG 25 Schematic of the GSM Rx Path
TP3
TP2
nztG_\WG
kjzVwjzG
TP1