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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
4. TROUBLE SHOOTING
LGE Internal Use Only
(3) Checking RX I/Q
Redownload software and calibration
again
Similar?
No
Replace U501
Yes
No
Graph 4.2.3
Check C516, C517.
Check if there is any
Major difference
Refer to
Graph 4.2.3
Figure 4.2.3
CHECKING FLOW
WAVEFORM
TP3 & T43
TP1 & TP2
CIRCUIT
TP1
TP2
TEST POINT
TP3
TP4
RX_I
RX_Q
1
O
D
L
V
n
0
2
2
9
0
5
C
Q
B
B
_
C
C
V
4
2
E
F
_
C
C
V
1
7
1
F
E
R
_
C
C
V
12
VCC_TXVCO
13
VDD
15
VLDO1
16
VLDO2
VLDO3
9
RX1800
28
27
RX1800B
RX1900
26
RX1900B
25
RX850
32
31
RX850B
RX900
30
29
RX900B
K
L
C
S
6
5
A
T
A
D
S
N
E
S
7
11
TXOP_HI
TXOP_LO
10
C
N
_
C
F
A
V
8
1
14
VBAT
4
I
B
B
_
C
C
V
33
GND
2
I
B
I
3
8
C
N
3
2
Q
B
Q
2
2
0
2
N
I
F
E
R
B
N
I
F
E
R
9
1
P
O
_
F
E
R
1
2
1
0
5
U
8
4
5
6
D
A
1
0
1
0
8
2
0
Y
S
U
E
7
1
5
C
p
9
3
4
1
5
C
u
1
1
O
D
L
V
p
9
3
6
1
5
C
10
R503
N
I
N
Q
P
Q
P
I
TP4
TP3