LG AR140B, Руководство по обслуживанию

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5. TROUBLE SHOOTING
5.12.2. Checking PLL Control signals
Check U400
Yes
No
No
Yes
Control Signal is OK.
See next page to check
Mobile SW & FEM.
No
Yes
Checking Flow
Check U400
Check U400
Checking Points
TP3 (RF_CLK)
Figure 5. Transceiver
Figure 6. Transceiver Circuit
Waveform
Figure 7. PLL Control Waveform
RF Transceiver Circuit Diagram
EN Signal(TP1) is OK ?
DA(Data,TP2) is Normal
?
CLK(Clock,TP3) is Normal
?
RF_EN(TP1)
RF_CLK(TP3)
RF_DATA(TP2)
TP2 (RF_DATA)
U400
TP1 (RF_EN)
TP3
TP2
TP1
C419
100n C432
100n C404
100n
820
R403
C418
100n
1000P C405
C406 47N
0
0
4
U
2
7
2
6
B
M
P
20
19
18
17
16
15
14
13
1
2
2
1
2
2
1
1
3
2
0
1
4
2
9
5
2
8
6
2
7
7
2
6
8
2
5
9
2
4
0
3
3
1
3
2
2
3
1
5
6
8
9
0
1
GND4
GND3
VDDMIX2V8
VDDTX2V8
TX2
TX1
VDDTX1V5
VBIAS
FE2
A
1
E
F
X
A
8
V
2
S
AI
B
D
D
V
B
X
1
X
R
X
B
1
X
R
8
V
2
GI
D
D
D
V
X
2
X
R
A
D
2
X
R
K
L
C
2
D
N
G
5
V
1
GI
D
D
D
V
X
3
X
R
3
S
Y
S
F
3
X
R
2
S
Y
S
F
X
4
X
R
O
X
4
X
R
X
O
X
5
V
1
A
N
L
D
D
V
GND1
FSYS1
VDDXO2V8
EN
VDDVCO2V8
VCO_RC
VDDRX1V5
VDDRX2V8
26MHZ
X400 NX3225SA
2 1
3
4
GND2 HOT2
HOT1 GND1
RF_EN
RF_DA
RF_CLK
26MHZ_MCLK
QX
Q
IX
I
BT_CLK
TP3
TP2
TP1