LG KU730 Service Manual page 82

4.6.1 Checking VCO Block
TP5
TP
TP6
TP5
R115
30
R116
15
R124
51
Test Point (TXVCO Level)
TP4
TP1
925-960 MHz
L122
C128
NA
1000p
L124
22nH
L126 12nH
MQW5V0C869M U102
10 3
VC VB
1 9
OUT_GSM SW1
5 11
OUT_DCSPCS SW2
8 2
C142
GND5 GND1
12 4
GND6 GND2 33p
13 6
GND7 GND3
14 7
GND8 GND4
Schematic of RF TXVCO
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4. TROUBLE SHOOTING
TP6
TP6
TP4
TP
TP
TP3
TP2
TP
TP1 TP
TP3
TP2
(1%)
R110 100 R111
C130
R114
120p
C134 5.6n
(PPS)
FB100
VREG_RFTX_2.85V
R117 100
GSM_TX_VCO_0_EN_N
R118 100
GSM_TX_VCO_1_EN_N
C141 VREG_MSMP_2.7V
10u
VREG_RFTX_2.85V
(1%)
0
(1%)
C131
33
330p
R119
100
C154 C155
C153
10u
0.1u 100p