LG KE820 - Page 107

5. Trouble shooting
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5.12.11 Checking Transceiver Output Signals
1V5_RF
1u
C417
NA
R420
C457
10u
R418
10
R421
NA
R415
NA
0.1u
C425
0
R413
R416
NA
2V85_RF
0
R412
VBIAS
VCO_RC
18
31
VDDBIAS2V8
8
VDDDIG1V5 VDDDIG2V8
5
21
VDDLNA1V5
VDDMIX2V8
39
VDDRX1V5
19
20
VDDRX2V8VDDTX1V5
35
38
VDDTX2V8 VDDVCO2V8
17
VDDXO2V8
15
XO
11 12
XOX FSYS2 FSYS3
9
13
GND1
GND2
26
40
GND3
GND4
41
29
RX1
RX1X
30 27
RX2
RX2X
28
RX3
24 25
RX3X
RX4
22 23
RX4X
36
TX1
TX2
37
34
U402
PMB6272
A
1 2
AX B
3 4
BX CLK
7 6
DA
16
EN
FE1
32
FE2
33
14
FSYS1
10
0.1u
C424
HBAND_PAM_IN
LBAND_PAM_IN
Figure 22. Transceiver Output Circuit
Figure 23. Transceiver Output
Table 3. Transceiver Output Operation
Checking Points
U40
LBAND PAM IN
HBAND PAM IN (DCS/PCS)
MODE Transceiver Output
GSMK Fixed
8PSK Ramp Burst Control