Samsung SYNCM.400B - No Raster Troubleshooting

6 Troubleshooting
6-2 CKA42*7L/5227L
6-3 No Raster
Check the horizontal drive
circuits. (IC401)
Does the drive pulse appear
at Pin 26 of IC401?
Yes
No
Check Q403 and T401
Does the drive pulse
appear at the collctor of
Q403?
Yes
No
Check its related circuits
(R414 and C411)
No
WAVEFORMS
25
23
Check flyback pulse at the
collector of Q402 connection of
CN502 and its related circuits
(D403, D409 and T501)
Does the drive output
pulse appear at the base
of Q402?
Yes
26
27
4.76 V (IC401, #26)
CH1 P-P = 4.76 V CH1 RMS = 3.652 V
23
29.4 V (Q403, Collector)
CH1 P-P = 29.4 V CH1 RMS = 13.16 V
25
10.4 V (Q402, Base)
CH1 P-P = 10.4 V CH1 RMS = 1.384 V
26
1.104 kV (Q402, Collector)
CH1 P-P= 1.104 kV CH1 RMS = V
27