Checking Umts Block - LG U250 Service Manual

4.6 Checking UMTS Block

4.6.1 Checking Tx level
ANT101
1p
C437
TP2
WCDMA
Rev.D
L404
1.8nH
FL104
4 1
PGND RX
3 2 C162
ANT TX
3.3p
ACMD-7602
0.5p
L125
TP4
ANT102
C450
22p
C102
L101
NA
NA
+VPWR
TP3
L123
1nH
C164
0.5p
20dB
U102
CP0402A1950DNTR
PWR_DET
R120
R121 R122
47
130 130
7dB
For testing, Max power of UMT 2100 is needed.
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4. TROUBLE SHOOTING
TP1
TP2
TP3
TP1
SW100
G2
ANT RF
G1
KMS-507
Rev.D
C155 C158 C159
4.7u
15p 15p
WS2512_TR1G U103
10 1
VCC2 VCC1
9 2
GND4 RFIN
Rev_1.0
8 3
RFOUT GND1
7 4
GND3 VCONT
6
C165 GND2
11 5
1p BGND VREF
C192
100p
C101
56p
L102
100nH
U500
Rev_1.0
C154
1.5p
+VPWR
L122 C157
NA 10nH
PA_R0
TP4
TR100
KRX102U
PA_ON
VREG_TCXO_2.85V
C170
0.1u
FL102
EFCH1950TDF1
4 5
O1 G3
1
IN
G2 G1
3 2
Rev.B