Samsung CKB5237L Service Manual page 36

6 Troubleshooting
6-7 No OSD Displays
There is video but no OSD.
While pushing a front
control button does any pulse
appear at Pins 18 and 19 of
IC202?
Yes
Does the horizontal
33 flyback pulse appear
at Pin 5 of IC104?
Yes
Does the vertical
blanking pulse appear at
32
Pin 18 of IC104?
Yes
Does the OSD video
signal appear at Pins
7 and 8 of IC104?
Yes
Does the OSD output
signal appear at Pins
21, 22 and 23 of IC104?
Yes
OSD Gain (IC101 Pin 11)
6-6
When you push a button
No
on the front control panel
does the voltage vary at Pins
18 and 19 of IC202?
Check IC202.
Check horizontal flyback pulse
No
generation circuit.
(T402 Pin 10, and Q102)
Check vertical blanking pulse
No
generation circuit.
(Q301 and Q103)
No
Does DC 5 V appear at
Pin 4 of IC104?
Check IC102
No
Check the pins of IC600
and the related circuit.
Check IC102
Check the push buttons
Yes
main board SW1 ~ SW4
No
Yes
No
and CN102(A).
WAVEFORMS
32 5.04 V (Q103, Collector)
CH1 P-P = 5.04 V CH1 RMS = 4.952 V
33 4.96 V (Q102, Collector)
CH1 P-P = 4.96 V CH1 RMS = 4.472 V
CKB5237L/7227L