LG KE600 - Cell Phone Service Manual page 108

5.15.6 Checking RX I/Q Signals
2V7_VCXO
26MHz
VCC GND
4 2
C641 C632
NA
1u OUT VCONT
3 1
X601
C633 100p R620 0
2V85_RF
1V5_CORE
R622 10
C636
C637
0.1u
0.1u
Figure 14. RX I/Q Circuit
Checking Points
TX_I
(IX)
RX_I
(I)
Figure 15. RX I/Q
R619 680
AFC
C634
22p
C635 1000p
BT_CLK
RF_CLK
RF_DA
QX
Q
IX
I
U602
RX_Q
(Q)
- 109 -
Checking Flow
Check RX I/Q Signals
Signals are
Normal ?
Ye
RX Part is OK.
Check Base Band Circuit
or
Re-Download S/W and Cal
RX_I
RX_Q
TX_Q
(QX)
RX_I
RX_Q
Figure 16. RX I/Q Waveform
5. Trouble shooting
N Replace
Transceiver
PMB6272(U602)
RX