LG CF-21Q20EH Service Manual page 15

Don t Catch Channel
'
Check the voltage at
pin9 of Tuner(33V)
0V
Check & Replace
F854,D861,R103,ZD101
Check the waveform at
pin14 of IC141(CVBS)
No
Check & Replace
Z101,IC141
No PIP
No
Check & Replace
ICN101 & IIC Bus
No
Check CP131
Check & Replace
ICP01 & IIC Bus
Check RP11~14
,CP15~18
33V
Check the voltage at
7
pin7 of Tuner(5V)
5V
Yes
Check the waveform at
pin21 of IC01(CVBS In)
Check & Replace
IC01,IC141
Is there video signal at
pin13 of ICN101
Yes
Is there video signal at
pin28 of ICP101?
Abnormal
Abnormal
- 15 -
0V
Check & Replace
L102,Tuner
Check & Replace
ICN01
Yes
Check pin15~18
of ICP01
Normal
Check pin27~30
of IC01
Normal
Check & Replace
IC01