LG GX500 Service Manual page 104

GX500 Operational Description
4.13.5 Checking PAM Control Signals
12 1
DCS_PCS_OUT DCS_PCS_IN
10 2
GSM850_900_OUT MODE_SELECT
13 3
BY_CAP1 BS
U402
9 4
TQM7M5005H
BY_CAP2 VBATT
14 5
GND1 VRAMP
11
GND2
8 6
GND3 TX_EN
15 7
PGND GSM850_900_IN
OK
C414 C437
33u
1u
OK
SIM1 Circult
SIM1 Circuit
Figure 4-53. PAM Control Signals Circuit
SIM1
Figure 4-54. PAM Output
Table 4-4. PAM Mode Operation
MODE MODE
GMSK LOW
8PSK HIGH
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Only for training and service purposes
TP1(PA_LEVEL)
TP1(PA_LEVEL)
R407
HBAND_PAM_IN
100P
PA_MODE
S1_PA_BAND
R403
PA_LEVEL
10K
TXON_PA
R404
LBAND_PAM_IN
100P
C441 C415 C429
C420
C434 100P 100P 47P 100P
27P
TP2(TXON_PA)
TP2(TXON_PA)
TP(PA_MODE)
TP3(PA_MODE)
TP1(PA_LEVEL)
TP2(TXON_PA)
TP3(PA_MODE)
PA_LEVEL
Ramp Burst Control
Control Amp bias
PGND GSM850_900_IN
15 7
GND3 TX_EN
8 6
GND2
11
GND1 VRAMP
14 5
TQM7M5005H
BY_CAP2 VBATT
9 4
U602
BY_CAP1 BS
13 3
GSM850_900_OUT MODE_SELECT
10 2
DCS_PCS_OUT DCS_PCS_IN
12 1
C613
1u
TXON_PA
HIGH
HIGH
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4. TROUBLE SHOOTING
Revision A
R601
100P
R605
10K
C620 C631 C623 C639
C622
C640
100P 100P 100P 47P
33u
27P
SIM2 Circult
SIM2 Circuit
SIM2
LGE Internal Use Only
TXLB
PA_EN
TX_RAMP
S2_PA_BAND
PA_MODE_2