LG KS20 - Checking Rf Tx Level

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4. TROUBLE SHOOTING
4.7.1 Checking RF Tx level
4.7.2 Schematic of RF Tx level
LGE Internal Use Only Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
HIGH
(1608)
GSM 900 RX
MODE
WCDMA
HIGH
GSM(925-960 MHz)
Rev.F
-
TQM7M5008
DCS(1805-1880 MHz)
ANT_SEL1 ANT_SEL2
HIGH
GSM 1800/GSM 1900 TX
ANTENNA SWITCH MODULE LOGIC
-
GSM 1900 RX
LOW
GSM
GSM 1800 RX
LOW
PCS(1930-1990 MHz)
HIGH
-
LOW
LOW
LOW
SFAY0010001
GSM_PA_BAND
GSM 850/GSM 900 TX
LOW
GSM 850 RX
GSMLOW
LOW
LOW
LOW
DCS/PCS
LOW
LOW
HIGH
HIGH
ANT_SEL0
HIGH
LOW
14
GND6
16
GND7 GND8
17
GSM_IN
7
GSM_OUT
9
3
TX_EN
VBATT
4
VCC
12
6
VRAMP
33p
C516
TQM7M5008
U501
BS
2
DCS_PCS_IN
1
15
DCS_PCS_OUT
GND1
5
8
GND2
GND3
10
11
GND4
13
GND5
ANT500
33p
C540
4.7p
C539
33p
C514
33p
C503L500
3.9nH
4.7p
C502
L514
12nH
33p
C515
ANT501
6.8nH
L513
C534
22u
VRF_SMPS
C509
0.1u
VBAT
100nH
L502
100p
C533
15p
C541
L512
2.2nH
13
4
GND4
5
8
GND5
10
GND6
12
GND7
GND8
17
18
GND9
7
NC
22
PCS_RX1
PCS_RX2
21
PGND1
25
PGND2
26
9
UMTS_TX_RX
14
VC1
15
VC2
VC3
16
VDD
ANT
11
DCS_PCS_TX
3
DCS_RX1
20
DCS_RX2
19
EGSM_RX1
24
23
EGSM_RX2
6
EGSM_TX
1
GND1
2
GND2
GND3
FL500
LSHS-M090UE
0
R500
15nH
L501
KMS-506
ENWY0002301
ANT
G1
G2
RF
SW500
NA
C506
68p
C53
C505
1.5p
ANT_SEL2
ANT_SEL1
ANT_SEL0
TP1
TP2
TP3