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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
4. TROUBLE SHOOTING
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4.4.3 PAM Control Signal part
Check Control
Signals
Signals are
Normal ?
Check
Locosto(U102)
Yes
No
PAM Control Signal
is OK.
See next page to
check
ASM & Mobile SW
Circuit.
PA Enable
①
②
CHECKING FLOW
U400
FL400
SW400
X101
U102
< PAM Control Placement>
Tx Ramp
②
①
< PAM Control Circuit>
< PAM Control Wave >
close to DBB
C407
0.01u
DNI
C419
C402
1.5p
C401
2.2p
C409
39p
15p
C410
C413
47p
1.5p
C414
C405
ECCH0003002
10u
GND5
10
12
GND6
GND7
13
14
GND8
16
GND
9
P_GND
21
RSVD_GND
19
20
VA
P
C
VBA
TT
17
VCC1A
2
VCC1B
6
C2012JF1A106ZT
U400
SKY77318
1
BS
3
DCS_PCS_IN
DCS_PCS_OUT
15
EGSM_IN
4
EGSM_OUT
11
18
ENABLE
5
GND1
GND2
7
GND3
8
9
GND4
68p
C400
0.01u
C406
VBAT
10nH
R403
L404
10
L400
3.3nH
0.5p
C421
2.7nH
L410
0.01u
C408
L403
18nH
L401
1nH
L411
3.3nH
VDDRF1
C423
27p
0.5p
C422
1.5p
C403
1p
C417
R404
47
DNI
180p
C412
C418
C415
0.5p
R405
47
15K
R400
TXLB
TXHB
TX_RAMP
PA_BAND
PA_EN
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②
①
-38-
②
①
Tx Ramp