LG KG920 - Page 83

(1) Checking PAM Control Signal
4. TROUBLE SHOOTING
- 84 -
TEST POINT
CIRCUIT
U501
R502(PAM_EN)
R515(TX_RAMP)
Figure 4-16.
3dB ATTEN
(PA)
2dB ATTEN
(GPO_16)
430
R512 R513
430
10K
R515
R508
300
GSM_IN
11
GSM_OUT
21
PGND
19
RSVD_GND
VAPC
20 17
VBATT
2
VCC1A
6
VCC1B
BS
1
DCS_PCS_IN
315
DCS_PCS_OUT
ENABLE
18
GND1
5
GND2
7 8
GND3 GND4
9 10
GND5 GND6
12 13
GND7 GND8
14
GND9
16
4
SKY77328
U501
R514
0
10p
C512
18
R507
33p
C509
2V8_VEXT
R510
12
1000p
C508
C519
27p
0.01u
C513
300
0.01u
R509
C514
0
R502
TX_RAMP
PA_EN
CIRCUIT
Go to Next Step
Similar?
Yes
No
Check TX_RAMP and PA_EN
Check if there is
Any Major Difference or not
Go to Next Step
Similar?
Yes
No
Go to Next Step
Similar?
Yes
No
Redownload S/W
Check TX_RAMP and PA_EN
Check if there is
Any Major Difference or not
Refer to Graph 6
Figure 4-17.
Figure 4-18.
WAVEFORM
Graph 4-6.