LG LG9200 Service Manual page 78

RX Part Trouble Shooting RX Part Trouble Shooting(2)
1. Check Ant. SW and Mobile SW
GSM_ON
➀ Check Dual And gate input signals.
➁ Check Ant. SW control signals (Outputs of And gate).
GSM TX
PCS TX
RX
➂ If VC1 and VC2 are differ to above logic table, change U501(dual and gate).
1pin - PCS_ON
2pin - TX_ON
3pin - VC1
6pin - GSM_ON
7pin - VC2
U501
VC2
PCS_ON
TX_ON
VC1
VC1 VC2
1
0
0
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4. TROUBLE SHOOTING
0
1
0