LG 29FU1RNX Service Manual page 18

4.NO RASTER
Is the voltage at VCC of
IC100 ST_1.8V and ST_3.3V ?
Does the square
waveform from Pin 11
of IC106 appear?
NO
Check / Replace
IC106
Is the waveform at
Drain Q422 normal?
NO
Check / Replace
Q422,T402
Check +B voltage
126V~130V(128V)
OK
NO
Check ST_Voltage
Check IIC bus lines
YES
(SDA,SCL)
YES
- 18 -
OK
OPEN
Check F1701
Fuse on PSW
Board
Check / Replace
F1701
OK
OV
Check the voltage
of C804
OV
Check the voltage
at pin 2 of IC801
Check / Replace
IC801
Check the voltage
atJ830 ST 5V
Check the output
IC830,IC840,IC843
Check / Replace
D801