LG -200 Service Manual page 62

I Component list of LG200 M/B (1-2)
Location
1 U41 2.9V Voltage comparator
2 U11 Provide SIM card power (3V ,5V)
3 J3 SIM LOCK
4 U1 SC 1689
5 U25 Provide power for U1(SC1689) V
6 U27 Provide power for POWER Control Loop V
7 U26 Provide power for U31 (W3020)
8 U3 GSM pre-amplifier
9 U4 GSM TX filter
10 U9 GSM power amplifier, for damage caused by 900 MHz network failure.
11 U43 DCS pre-amplifier
12 U44 DCS TX filter, for damage caused by 1800 MHz network failure.
13 U32 DCS power amplifier, for damage caused by 1800 MHz network failure.
14 J4 "Antenna switch, for damage caused by antenna transmit or receiving problem.
Normal: Short Abnormal:Open"
15 U23 Multiplexer, for damage or cold soldering caused by transmit or receiving problem.
16 U21 OP AMP: control Power Control Loop
17 U54 Electronic switch: control Power Control Loop
18 J6 Battery connector
19 U35 Provide 13MHz TCXO, for damage caused by no network service.
20 U24 Provide power for main system U15(CPP) and Keyboard.
21 U38 Invert gate, for damage or cold soldering caused by Carkit failure, or Download data failure.
22 U39 NAND gate, for damage or cold soldering caused by total damage.
LG-200 M/B(1-2)
=3.8V V =2.85V
in out
=3.8V V
in out
V =3.8V V =2.85V
in out
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4. TEST POINT DATA
=2.85V ± 0.5