LG U830 KU830 Service Manual page 92

4.6.2 Checking Ant. SW Module
Refer to chapter 4.4
4.6.3 Checking RF Tx level
TP2
TP1
L0
L1
TP2
TP3.
Test Point (RF Tx Level) BOT & TOP
L500
SW500
33p
C500
G2
ANT RF
G1
KMS-512
L502
NA
U500
19
VDD GSM850_RX1
GSM850_RX2
18
C502 C503 CTRL1 GSM900_RX1
22
10p 0.1u CTRL2 GSM900_RX2
GSM1800_RX1
GSM1800_RX2
10
GND1 GSM1900_RX1
12
GND2 GSM1900_RX2
13
GND3 WCDMA2100
15
GND4
17
GND5 DGM085M01
20
GND6
C506 C507
21
GND7 GSM850900_TX
23
GND8 GSM18001900_TX
100p 100p
C518 C522
100p
2.7p
L519
L520 5.6nH
12nH
C526
L522
2.7nH
6.8p
16
DCS_PCS_OUT
10
GSM_OUT
Schematic of RF TX Level
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4. TROUBLE SHOOTING
TP1
7
8
5
6
1
2
3
4
9
16
14
TP3
R504
GSM_PA_RAMP
2.2K
C517
68p
C519 22n
+
C524 C523
100u
33p
C532
51p
1
DCS_PCS_IN
7
U502 GSM_IN
AND0041
3
TX_EN GSM_PA_EN
2
BS GSM_PA_BAND
C544 C545
1000p 1000p