LG S5000 Service Manual page 52

(3) Checking Mobile SW & FEM
Test Points
Circuit Diagram
TP500 TP501 TP502
C509
1p
R504
ANT
3.9nH
C513
NA
KMS-506 SW500
C520
22p
GND13 PCS_RX2
24
GND12 PCS_RX1
23
GND11 DCS_RX2
22
GND10 DCS_RX1
21
GND9 EGSM_RX2
20
GND8 EGSM_RX1
19
GND7
18
GND6
17
GND5
16
GND4
7
GND3 DCSPCS_TX
6
GND2 EGSM_TX
4
GND1
2
HWXQ511
FL500
FEM
C539 C540
270p 270p
SW500.ANT SW500.RF
SW500
C501
1p
L500
NA
15
14
13
12
11
10
5
8
R511 0
ANT_SW1 (GPO_9)
R512 0
ANT_SW2 (GPO_11)
- 53 -
4. TROUBLE SHOOTING
FL500
VC_DCSPCS
VC_EGSM
Figure 4-4
Waveform
FL301. 10
VC_DCSPCS VC1
VC_EGSM
VC2
ANT SW Control GSM& DCS RX Mode
Graph 4-2
ANT_SW1
GSM_TX HIGH
DCS_TX LOW
RX LOW
Table 4-1
Low Low Low
Low Low Low
ANT_SW2
LOW
HIGH
LOW