Samsung DP14LS Service Manual page 43

6 Troubleshooting
6-2-21 Horizontal Blank Failure
Symptoms: – Dark image and if shifting image to left or right side, image is rolled.
– Raster left or right side is rolled.
Is H_Blank waveform on
31
Q510's collector?
No
Are Q504 and D515 ok?
Yes
Check and replace C501, C502,
C503, R504.
6-2-22 Whistle Sound
Check trans coil (L401, T501, T601, CRT)
6-2-23 Spot at Center During Power Off
Does G1 voltage vary from
–60~80 Vrms to –200 Vrms during
power off time? (After falling
32
down to –200V, G1 voltage is
slowly increased to 0V).
No
Are 12 V line and Q501 ok?
Yes
Check and replace C506, D504, R515,
R516, R517.
6-24
Yes
Check CN105 and CN202.
Check and replace IC101.
No
Replace it.
Yes
Check and replace CRT.
No
Replace it.
WAVEFORMS
31 5.36 V (Q510, Collector)
CH1 P-P = 5.36 V CH1 RMS = 4.210 V
WAVEFORMS
158 V (CN105, G1)
32
CH1 P-P = 158 V CH1 RMS = 151.1 V
DP14L*/DP15L*