LG -T300 Service Manual page 69

4. TROUBLE SHOOTING
(2) Checking Mobile SW & TX Module
TEST POINT
TP5
CIRCUIT
R401 1K
TX_RAMP
TX_EN
BS1
BS2
BS3
SW401
TP5
C404 7p
TP1
C442
C405
C401
C407 1.2p
DNI
5.6n
1p
LGE Internal Use Only
TP1
TP4
Figure 4.3.4
VBAT
C421 C413 C424 C423 C426
1n 1n 1n 1n 39p
C412
C425 C419
10n 33p 4.7u
17 1
GPCTRL2 GND1
16 2
GND9 GND2
C409 56p
15 U401 3
GND8 RFIN_LB
14 4
ANT GND3 L404 3.3n
C410 22p
13 5
DCS
RX4 RFIN_HB
PCS 12 6
RX3 GND4
L405
1.5n
C422
1p
TP2
GSM850
EGSM
RX34X
FL402 C411 1.8n
C416 33p DCS
1 8
IN_1842_5 OUT_1842_5
L402 L408
C417 33p PCS 1.8n
4 9
IN_1960 OUT_1960 68n
2 7
GND1 GND2
3 6 RX34
C420 1.8n
GND3 GND4
5 10
GND5 GND6
TP
1805M1880M,1930M1990M
22p
L409
RX12X
FL401
GSM850
C418 33p
1 8
IN_881_5 OUT_881_5
L407
C427 33p
EGSM 12n L410 33n
4 9
IN_942_5 OUT_942_5
2 7
RX12
GND1 GND2
3 6
GND3 GND4 L406 22p
5 10
GND5 GND6
869M894M,925M960MHz
4. TROUBLE SHOOTING
CONTROL LOGIC
EGSM Tx
TP4
C415
4.7u
GSM_OUT
L403 3.3n
DCS_PCS_OUT
BS3
Tx_EN
BS1
BS2
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Copyright © 2010 LG Electronics. Inc. All right reserved.
TP2
TP3
BS3
BS2
BS1
TX EN
TX Ramp
Only for training and service purposes