LG GT350, Руководство по обслуживанию

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Only for training and service purposes
4. TROUBLE SHOOTING
LG Electronics
92/115
LGE Property
4.13.1 Checking VCTCXO Circuit
See RX Part “1. Checking DCXO Circuit”
4.13.2 Checking PLL Control Signal
See RX Part “2. Checking PLL Control Signal”
4.13.3 Checking TX I/Q Signals
Check TX I/Q Signals(TP1~TP4)
Signals are
Normal ?
Replace
Transceiver
PMB6272(U601)
Yes
No
TX Part is OK.
Check Base Band Circuit
or
Re-Download S/W and Cal
TP4(QX
TP3(Q) TP2(IX)
Checking Flow
TP1(I)
G
Figure 17. TX I/Q Circuit
LG Electronics
92/115
LGE Property
4.13.1 Checking VCTCXO Circuit
See RX Part “1. Checking DCXO Circuit”
4.13.2 Checking PLL Control Signal
See RX Part “2. Checking PLL Control Signal”
4.13.3 Checking TX I/Q Signals
Check TX I/Q Signals(TP1~TP4)
Signals are
Normal ?
Replace
Transceiver
PMB6272(U601)
Yes
No
TX Part is OK.
Check Base Band Circuit
or
Re-Download S/W and Cal
TP4(QX
TP3(Q) TP2(IX)
Checking Flow
TP1(I)
G
Figure 17. TX I/Q Circuit
X601
26MHZ
TSX-3225
2 1
3
4
GND2 HOT2
HOT1 GND1
U601
PMB6272
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
33
34
35
36
37
38
39
40
41
GND4
GND3
VDDMIX2V8
VDDTX2V8
TX2
TX1
VDDTX1V5
VBIAS
FE2
A
1
EF
X
A
8
V2
S
AI
B
D
D
V
B
X1
X
R
X
B
1
X
R
8
V2
GI
D
D
D
V
X2
X
R
A
D
2
X
R
KL
C
2
D
N
G
5
V1
GI
D
D
D
V
X3
X
R
3
S
Y
SF
3
X
R
2
S
Y
SF
X4
X
R
O
X
4
X
R
X
O
X
5
V1
A
NL
D
D
V
GND1
FSYS1
VDDXO2V8
EN
VDDVCO2V8
VCO_RC
VDDRX1V5
VDDRX2V8
0.001uF C616
0.047uF
C617
R612
820
RF_EN
RF_DA
RF_CLK
26MHZ_MCLK
QX
Q
IX
I
26MHZ_BT
TP1(I)
TP2(IX) TP(Q) TP4(QX)