LG GT350 - Page 90

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4. TROUBLE SHOOTING
LG Electronics 87/115 LGE Property
5.12.2 Checking PLL Control signals
Check U601
Yes
No
No
Yes
Control Signal is OK.
See next page to check
Mobile SW & FEM.
No
Yes
Check U602
Check U603
TP1 (RF_EN) TP3 (RF_CLK)
Checking Points
Figure 5. Transceiver
Figure 6. Transceiver Circuit
Waveform
RF Transceiver Circuit Diagram
EN Si
g
nal
(
TP1
)
is OK ?
DA(Data,TP2) is
Normal ?
CLK(Clock,TP3) is
Normal ?
TP2 (RF_DATA)
U601
RF_EN(TP1)
RF_CLK(TP2)
RF_DATA(TP3)
TP1
TP2
TP3
Checking Flow
Figure 7. PLL Control Waveform
X601
26MHZ
TSX-3225
21
3
4
GND2 HOT2
HOT1 GND1
U601
PMB6272
20
19
18
17
16
15
14
13
12
2
1
22
11
32
01
42
9
528 6
2
7
726
8
2
5
924 033
13
2
23
1
33
34
35
36
37
38
39
40
41
GND4
GND3
VDDMIX2V8
VDDTX2V8
TX2
TX1
VDDTX1V5
VBIAS
FE2
A 1EF
XA 8V2SAIBDDV
B X1X
R
XB
1XR
8V2
G
IDD
DV X
2X
R
A
D
2XR
K
L
C 2
DN
G
5V
1GI
D
D
DV
X3
X
R
3SYS
F 3XR
2SYSF X4X
R
OX 4X
R
X
OX 5V
1AN
L
D
DV
GND1
FSYS1
VDDXO2V8
EN
VDDVCO2V8
VCO_RC
VDDRX1V5
VDDRX2V8
0.001uFC616
0.047uF
C617
R612
820
RF_EN
RF_DA
RF_CLK
26MHZ_MCLK
QX
Q
IX
I
26MHZ_BT
TP1
TP2
TP3