LG KU950 Service Manual page 86

Logic Table of the Antenna Switch
Mode
EGSM TX
EGSM RX
DCS/PCS TX
DCS RX
PCS RX
UMTS
Checking Switch Block power source
Check Soldering of
ANT_SEL0, 1, 2 High Level
2.5V < Voltgae < 3.0V
Check the Logic
in each mode
ANT_SEL0
HIGH
HIGH
LOW
HIGH
LOW
LOW
NO
YES
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4. TROUBLE SHOOTING
ANT_SEL1
HIGH
LOW
LOW
LOW
HIGH
HIGH
Check VCC
TP1 VREG_RFRX_0_2.85V
ANT_SEL2
LOW
LOW
HIGH
HIGH
LOW
HIGH