LG KE820 Service Manual page 107

5. Trouble shooting
5.12.11 Checking Transceiver Output Signals
LBAND_PAM_IN
HBAND_PAM_IN
R420
NA
Checking Points
2V85_RF
C417
1u
R412
R413 0
0
R421 R415 R416
NA NA NA
Figure 22. Transceiver Output Circuit
U40
Figure 23. Transceiver Output
MODE Transceiver Output
GSMK Fixed
8PSK Ramp Burst Control
Table 3. Transceiver Output Operation
1V5_RF
C457
10u
FE2
33
VBIAS
34
VDDTX1V5
35
TX1
36
TX2
37
VDDTX2V8
R418 38
VDDMIX2V8
39
10 GND3
40
C424 C425
0.1u 0.1u GND4
41
LBAND PAM IN
HBAND PAM IN (DCS/PCS)
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VDDRX2V8
20
VDDRX1V5
U402
19
VCO_RC
PMB6272
18
VDDVCO2V8
17
EN
16
VDDXO2V8
15
FSYS1
14
GND1
13