XG-C40XU/XE
TROUBLE SHOOTING TABLE FOR PC I/F UNIT-5
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) thru (31)
as well as (34) thru (41), except for
GND, of P8606?
Yes
Are there signals at TL8044 and
TL8046?
Yes
Is there signal at pin (Y11)(TL8612) of
IC8609?
Yes
Are there signals at pins (1) thru
(10) of IC8051?
Yes
IC8051 or its peripheral circuit or output
PWB faulty.
No
Terminal PWB,C8616 defective.
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.
C8702 or its peripheral circuit or signal
PWB faulty.
44
Checking the VGA's
red video circuit and
its peripheral
circuits
No
Is there signal at pin (139) of IC8606?
Yes
Are there signals at pins (21) thru (31)
No
as well as (34) thru (41), except for
GND, of P8606?
Yes
No
Are there signals at pins (112) thru
(119) of IC8020?
Yes
No
Are there signals at pins (69) 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 (144) of IC8606?
Yes
1
1