LG KM380t Service Manual page 85

6. Trouble shooting
6.12.4 RF Switch (Mobile Switch) circuit
√ Part Description of RF Switch
SW500: Mobile Switch (RF S/W) Connector
U102: Baseband Processor including RF transceiver
√ Check point of RF S/W (Mobile S/W)
GND500 GND501
C535
DNI
L519
1nH
C591
C536
DNI
C591
100p
15nH
L518
C537
DNI
LGE Internal Use Only
RF S/W Circuit
Is RF S/W short
between C591 &
R510?
YES
Check the next part
Fig 7 Debugging flowchart of RF S/W circuit
U502
LSHS-C085FB
R510
R510
11
G2
ANT RF
G1
0
SW500
RF-800
C546 DNI
C544 DNI C545 DNI
C552 C553 C554
C555
6.8p 6.8p
4.7p
4.7p
Fig 8 RF S/W circuit (U502)
- 86 -
NO
Replace
SW500
C547 DNI
L514 L515 L516 L517
4.7nH 4.7nH 3.9nH 3.9nH
Copyright © 2008 LG Electronics. Inc. All right reserved.
SW50
C591
R510
Only for training and service purposes