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6.12.4 RF Switch (Mobile Switch) circuit
√
Part Description of RF Switch
SW500: Mobile Switch (RF S/W) Connector
U104: Baseband Processor including RF transceiver
√
Check point of RF S/W (Mobile S/W)
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6. Trouble shooting
LGE Internal Use Only
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
RF S/W Circuit
Is RF S/W short
between TP1 &
TP2?
Replace
SW500
Check the next part
YES
NO
GSM850
PCS1900
DCS1800
GSM900
R504
100p
2.2nH
R596
C513
2.7p
18nH
L502
5.1nH
L504
3.3p
C518
L505
3.9nH
C503
120p
15p
C519
10nH
L584
15nH
L503
5.6p
C515
3.3p
C517
DUMMY
FEED
15
GSM1800_1900_TX
7
GSM1900RX_OUT1
GSM1900RX_OUT2
8
GSM850RX_OUT1
1
GSM850RX_OUT2
2
17
GSM850_900_TX
3
GSM900RX_OUT1
GSM900RX_OUT2
4
21
NC
19
VC1
VC2
20
ANT501
LSHS-C085FB
U501
11
ANT
GND1
9
24
GND10
GND2
10
12
GND3
GND4
13
GND5
14
GND6
16
18
GND7
22
GND8
23
GND9
GSM1800RX_OUT1
5
GSM1800RX_OUT2
6
C520
15p
KMS-512
SW500
ANT
G1
G2
RF
C514
2.7p
C516
5.6p
NA
L583
TP2
TP1
SW500
Fig 7 Debugging flowchart of RF S/W circuit
Fig 8 RF S/W circuit (U501)
TP1
TP2
Summary of Contents for KC550
Page 1: ...Date May 2008 Issue 1 0 Service Manual Model KC550 Service Manual KC550 Internal Use Only ...
Page 182: ...Note ...
Page 183: ...Note ...