LG KG245 Service Manual page 53

4. TROUBLE SHOOTING
(4) Checking RX IQ
TEST POINT
U401
Figure 4-5 (a). RX IQ Circuit
CIRCUIT
CHECKING FLOW
Check C425,C427.
Check if there is any
C425
C427
C423 2p
L403
5.6nH
C425 1.8p
C426 1.5p
L404
6.8nH
C427 1.5p
C428 12p
Figure 4-5 (b). RX IQ Circuit
Major difference
Refer to graph 4-3
Yes
Redownload software and calibration again
WAVEFORM
RFIPP
17
RFIPN
18
RFIDP
19
RFIDN
20
RFIEP
21
RFIEN
22
RFIAP
23
RFIAN
24
No No
Similar?
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Graph 3
U401
SI4210
Replace U401