Samsung SYNCM.400B Service Manual page 52

6-4 No Video
Power indicator is green
Does DC 12 V appear at
Pins 16 and 5 of IC101?
Yes
Does the video pulse
appear at Pins 4, 6 and 8
of IC101?
Yes
Does the video pulse
appear at Pins 13, 17 and
36
19 of IC101?
Yes
Does the video amplified
pulse appear at the Pins
8, 9 and 11 of IC102?
Yes
Does the video amplified appear
at the Pin #1, 3 and 5 of IC102?
Yes
Does the right R, G, B waveforms
appear at the disconnected
37
Video PCB from CRT?
Yes
Check screen VR of FBT and G2 Pin.
CKA42*7L/5227L
No
Check IC604.
No
Check signal cable
and signal source
No
Does the clamp signal
13
appear at Pin 10 of IC101?
No
Does the DC voltage appear
at pin 9 of IC 101?
No
Check IC101
Check IC101.
No
Check CRT.
No
Yes
No
Yes
6 Troubleshooting
WAVEFORMS
13 5.04 V (IC202, #37), Clamp
CH1 P-P = 5.04 V CH1 RMS = 5.024 V
36 4.92 V (IC101, #19)
CH1 ∆ = 4.92 V
CH1 RMS = 2.120 V
Check clamp circuit on
the Main PCB and
IC202 (pin #37).
Check contrast control
circuit (IC202 on the
Main PCB)
37 72.0 V (IC102, #1)
CH1 ∆ = 72.0 V
CH1 RMS = 45.76 V
6-3