TROUBLESHOOTING
NO RASTER
Check +B voltage at
E18
Is the voltage at pin12,
37 of IC501 8V?
Check the voltage of
C821
Check/Replace R410
Check Fuse of AC line
Check the voltage of
C806
Check the voltage of
pin4 of IC803
Check/Replace IC841,
IC843, D816, D815
Check the 8V, 5V lines
are shorted.
Check/Replace Fuse,
D801~804, TH801
Check/Replace
D801~804, R801
Check the voltage of
C827
Check/Replace
D808~811, T803
Check/Replace Q104,
Q802, RL801, IC842
Check/Replace
D805~806, IC803,
IC801
Does the square
waveform from pin40 of
IC501 appear?
Check/Replace IC501
No
No
No
No
110Vdc
Open
OK
254-380V
0V
10~14Vdc
0V
Lower than 18V
Normal 110Vdc
0V
OK
Yes
Yes
Yes
Yes
Check the voltage 8V
Line.
Check/Replace D816,
D821, IC841, D824
Is the waveform of
collector of Q401 normal?
Check I
2
C BUS lines
(SDA, SCL)
Check/Replace FR802,
D817, Q401, Q403, T451
Is the waveform of
collector of Q402 normal?
Check/Replace T406
Check/Replace Q402,
D403~4, C415,
C409~410
