Sharp Notevision PG-M25X, Service Manual

Page: 34 / 182

34
PG-M25X
Checking of Low-pass Filter Circuit
Yes
Is video signal is inputted to pins
(4), (8) and (12) of IC3851?
Is video signal inputted to pins
(24), (21) and (17) of IC3851?
Is the video signal inputted to pins
(8), (17) and (23) of IC8013
(AD9888) of the PC I/F unit?
No
IC3851 is defective.
If the picture quality is abnormal, check whether
or not the following voltages are outputted to
pin (28) of IC3851.
0.3 V for 480i, 1 V for 720p, 1080i, Check IC301.
Yes
Check Q3851, Q3852 and Q3853
and their periphery.
No
Is video signal is inputted to pins
(16), (20) and (24) of IC3001?
Yes
No
The low-pass filter circuit on the
input PWB is normal. Does the
picture appear?
Yes
No
Check pins (4), (8) and (12) of
SC3001.
Normal Abnormal
Check Q3854 and
Q3855.
Check the PC I/F unit.
Check DVI (analog)
input.
Yes No
Check the SOG
circuit or IC8013
and its periphery.
Check IC8013
and its periphery.
End