Samsung SYNCM.400B - Troubleshooting; No Power Troubleshooting; Horizontal Line on CRT Troubleshooting

CKA42*7L/5227L 6-1
6 Troubleshooting
Notes: 1. If a picture does not appear, fully rotate the brightness and contrast controls clockwise and reinspect.
2. Check the following circuits.
• No raster appears: Power circuit, Horizontal output circuit, H/V control circuit, and H/V output circuit.
• High voltage develops but no raster appears: Video output circuits.
• High voltage does not develop: Horizontal output circuits.
6-1 No Power
Does proper AC 90-264 Volts
appear between the positive and
negative poles of C604?
Check F601, L602 and TH602.
Check D604~D607, D609, IC602,
T601, OP601, and power circuit.
Yes
No
Check IC301 and its
related circuits
Check the power supply circuits
(D616)
Check the power supply circuits
(D608)
6-2 Horizontal Line on CRT
Does DC 13 V appear at
Pin 2 of IC301?
Does DC -11 V appear at
Pin 4 of IC301?
Yes
No
No
Replace IC301 or check its
related circuits
(D301, IC301 and R312)
Does the output pulse of
48 Vp-p appear
at Pin 5 of IC301?
Yes
Yes
No
WAVEFORMS
17
45.0 V (IC301, #5)
CH1 P-P = 45.0 V CH1 RMS = 5.48 V
17