LG GS290 - Page 88

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4. TROUBLE SHOOTING
GS290 Operational Description Revision B
LG Electronics 89/136 LGE Property
4.12.2. Checking PLL Control signals
Check U500
Yes
No
No
Yes
Control Signal is OK.
See next page to check
Mobile SW & FEM.
No
Yes
Checkin
g
Flow
Check U500
Check U500
TP1 (RF_EN) TP3 (RF_CLK)
Checkin
g
Points
Figure 5. Transceiver
Figure 6. Transceiver Circuit
Waveform
RF Transceiver Circuit Dia
g
ram
EN Si
g
nal
(
TP1
)
is OK ?
DA
(
Data
,
TP2
)
is Normal ?
CLK
(
Clock
,
TP3
)
is Normal ?
TP2 (RF_DATA)
U601
TP2
TP3
TP1
RF_EN(TP1)
RF_CLK(TP2)
RF_DATA(TP3)
Figure 7. PLL Control Waveform
26MHz
X500 TSX-3225
21
3
4
GND2 HOT2
HOT1 GND1
U500
PMB6272
20
19
18
17
16
15
14
13
1
2
2
1
22
11
32
0
1
42
9
52
8
62
7
72
6
8
2
5
924 0
33
132
23
1
33
34
35
36
37
38
39
40
41
GND4
GND3
VDDMIX2V8
VDDTX2V8
TX2
TX1
VDDTX1V5
VBIAS
FE2
A
1E
F
XA
8V
2SA
IB
DDV
B X
1X
R
XB
1X
R
8V
2G
ID
D
DV X2X
R
A
D 2X
R
K
LC 2DN
G
5V
1G
I
D
DDV X3XR
3SYSF 3XR 2SYS
F X
4XR
OX 4X
R
X
OX
5V1A
N
LDDV
GND1
FSYS1
VDDXO2V8
EN
VDDVCO2V8
VCO_RC
VDDRX1V5
VDDRX2V8
1nC516
C517
47n
0.1u
C535
0.1u
C506
R508
820
0.1u
C536
0.1u
C537
RF_EN
RF_DA
RF_CLK
26MHZ_MCLK
QX
Q
IX
I
CLK26M