T Rouble Shooting - LG CF-21Q20EH Service Manual

No Power ON(SMPS working)
Check the voltage of C402(+)
0V
Check & Replace
F854,D861,R405,R423
Check & Replace
D850, L853, T402.
No Power(Not working SMPS)
No Vertical Deflection
Check & Replace
FR403,FR413,D405,D406

T rouble Shooting

Check pin31 of IC01
High
Check & Replace
Q05, IC851, IC802(3), IC856
Check the H-Out voltage
at pin24 of IC01
NORMAL NO
Check the voltage at
33V
Check the voltage
at pin2 of FBT
0V
Check & Replace
Q401, Q402, T401.
Check the voltage of C804(+)
130~380V
Check the voltage
at pin4 of STR
0V
Check & Replace
T802, R809, D802.
Check the voltage
at pin1,6 of IC301
0V
Check & Replace
Low(=0V)
Check the voltage at
pin 54 of IC01.
3.3V
Check & Replace
IC01,FR403,R413,
D405,D406,IC301,
IC01
pin2 of FBT
110V
Check & Replace
SW1111,F1111,T801
D862,866,867,868
Z 18V
Check & Replace
IC801 and the
secondary section
+14V,-14V
Check the waveform
at pin35 of IC01
No
Check & Replace
IC01
- 12 -
0V
Check & Replace
IC853(3), FR406,
D408,D858,Q856
0V
Yes
IC301,D301