Sharp PG-C30XU Service Manual page 44

PG-C30XU
TROUBLE SHOOTING TABLE FOR PC I/F UNIT-3
Checking the S-
XGA's red video
circuit and its
peripheral circuits
Is there signal at pin (139) of IC8606?
Yes
Are there signals at pins (21), (22),
(24) thru (28) and (34) thru (41) of
IC8606?
Yes
Are there signals at TL8044 and
TL8046?
Yes
Is there signal at TL8612?
Yes
Are there signals at pins (1) thru (9) of
IC8051?
Yes
CON4 (P8405), IC8051 or their
peripheral parts faulty.
No
output PWB faulty.
No
IC8606 or its peripheral circuit faulty.
No
IC8025 or its peripheral circuit faulty.
IC8020 or its peripheral circuit faulty.
No
IC8029 or its peripheral circuit faulty.
No
IC8609 or its peripheral circuit faulty.
output PWB faulty.
44
Checking the VGA's
red video circuit and
its peripheral
circuits
No
Is there signal at pin (139) of IC8606?
Yes
No
Are there signals at pins (21), (22),
(24) thru (28) and (34) thru (41) of
IC8606?
Yes
No
Are there signals at pins (112) thru
(119) of IC8020?
Yes
No
Are there signals at pins (67) thru (73)
and (189) thru (192) of IC8020?
Yes
Check the video
system's red video
circuit and its
peripheral circuits
No
Is there signal at pin (27) of CON2
(P8404) connector?
Yes
B
B