Checking Ant. Sw Module; Checking Rf Tx Level - LG U8500 Service Manual

4. TROUBLE SHOOTING

4.6.2 Checking Ant. SW Module

4.6.3 Checking RF Tx level

L1035
4.7nH
VREG_RFRX_0_2.85V
ANT_SEL0
ANT_SEL1
ANT_SEL2
TP2
GSM/DCS/PCS
Refer to chapter 3.4
Test Point (RF Tx Level)
TP1
ANT1000
ANT1001
SW1002
C1230
G2
ANT RF
G1
15p
KMS-512
C1112
L1034
0.5p
15nH
L1031 7.5nH
FXL4T245BQX U1008
1
VCCA _OE
14
VCCB
C1108 T__R
7
0.1u
GND1
8
GND2
15
BGND
13
B0 A0
12
B1 A1
11
B2 A2
10
B3 A3
Schematic of RF Tx Level
C1111 33p
M054E
U1006
9 2 12
CTRL1 RX_DCS1
4 13
CTRL2 RX_DCS2
6 11 14
CTRL3 RX_PCS1
20 15
CTRL4 RX_PCS2
16
RX_EGSM1
17
RX_EGSM2
2 8 3
UMTS TX_DCSPCS
3 1
TX_EGSM
4
5
R1050 R1049
0 0
C1100
C1104
0.01u
68u
L1026 L1025
NA NA
C1102
68p
15
DCS_PCS_OUT DCS_PCS_IN
11
U1005
GSM_OUT GSM_IN
SKY77328 ENABLE
19
RSVD_GND
- 90 -
TP1
TP2
TP3
ANT_SEL2 ANT_SEL1 ANT_SEL0
GSM 900 TX LOW LOW HIGH
GSM 900 RX/WCDMA LOW LOW LOW
DCS1800/PCS1900 TX HIGH HIGH LOW
DCS 1800 RX LOW HIGH LOW
PCS 1900 RX HIGH LOW LOW
TP3
+VPWR
C1098 C1070
10u
0.01u
3
4
18 100 R1041
GSM_PA_EN
1
BS GSM_PA_BAND
R1044 100
C1103 C1101
15p 15p