Sharp DT-400, Service Manual

Page: 41 / 156

41
XV-Z2000
DT-400
Feed the composite video signal to
INPUT 4. Select INPUT 4 using the
set's key or the remote controller.
Does the picture appear? Is the picture disturbed?
End.
YES
YES
NO
NO
Is the video signal inputted to the
pin (1) of IC3105?
YES
Check the VIDEO-IN signal
line of Q3505.
NO
Is there any input to pins (1), (3) and (5) of IC3104?
YES
Check IC3102 and its peripheral circuits.
NO
Is there any output from pins (16), (18) and (20) of IC3104?
YES
Check IC3104 and its peripheral circuits.
NO
Is the video signal inputted to pins (43), (48) and (54) of
IC6004 and the synchronized signal inputted to pins (30)
and (31)?
YES
Check IC3104, IC6001, IC6002 and their
peripheral circuits.
NO
Is each digital output coming on pins (64), (65), (66) and
(67) of IC6004?
YES
Check IC6004 and its peripheral circuits.
NO
Is there any output from IC8001 (DPORT)?
Check the formatter PWB.
YES
Check IC8001 and its peripheral circuits.
NO
YES
Check IC3501 and its
peripheral circuits.
YES
Checking the Video Input
Check IC3102 and its
peripheral circuits.
1
3
NO YES
Is synchronized signal
coming to pins (28) and
(29) of IC3102?
2
Memo
The composite video signal is Y/C-separated by IC3506 (3 Line
COM) and the resulting signals are inputted to pins (39) and
(41) of IC3105.
The video signal is outputted from color-difference pins (21),
(22) and (23) of IC3105.
Are the video signals inputted to
pins (39) and (41) of IC3105?
YES
YES
Is the video signal outputted from
pins (21), (22) and (23) of IC3105
inputted to pins (67), (68) and (69)
of IC3102?
Check IC3504, IC3506 and
their peripheral circuits.