LG KE600 - Cell Phone Service Manual page 113

5. Trouble shooting
5.15.12 Checking PAM Control Signals
NC3
20
NC2
15
NC1
10
LB_RFOUT
12
HB_RFOUT
18
LB_RFIN
7
VRAMP
6
VMODE
5
VBATT
4
TX_EN
3
BAND_SEL
2
HB_RFIN
1
RF3158 U601
VSUPPLY
C620 C621 C613
C638 C639
3p 10p
56p 18p 68u
Figure 26. PAM Control Signals Circuit
Checking Points
U601
U60
Figure 27. Transceiver
MODE MODE
GMSK LOW
8PSK HIGH
Table 4. PAM Mode Operation
LBAND_PAM_IN
HBAND_PAM_IN
PA LEVEL(R611)
Mode (R612)
TXON PA(R613)
PA_LEVEL
Ramp Burst Control
Control Amp bias
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R611 15K
PA_LEVEL
MODE
TXON_PA
PA_BAND
R612 R613 R614
100K 100K 100K
TXON_PA
HIGH
HIGH