Sharp XG-NV2SB, Service Manual

Page: 46 / 148

46
XG-NV2SB
TROUBLE SHOOTING TABLE FOR PC I/F UNIT-5
Yes
Yes
No No
Is there signal at pin (3) of IC8004?
Is there signal at pin (3) of IC8004?
LCP circuitry faulty.
Yes
Yes
No No
Is there signal at the base of Q31?
Is there signal at the base of Q31?
IC8004 or its peripheral circuit faulty.
Yes
Yes
Yes
No No
Is there signal at pin (6) of IC8009?
Is there signal at pin (6) of IC8009?
Q31 or its peripheral circuit faulty.
Yes
No No
Are there signals at BI1A0 thru -7 and
BI1B0 thru -7 of IC8025? Are there signals at VAB0 thru -7 of
IC8020?
IC8009 or its peripheral circuit faulty.
Yes
No
Are there signals at BI2A0 thru -7 and
BI2B0 thru -7 of IC8025?
IC8020 or its peripheral circuit faulty.
Yes
No
Are there signals at R1 thru -10 and
G1 thru -10 of IC8031?
IC8025 or its peripheral circuit faulty.
Yes
No
Are there signals at the bases of Q23
and Q25?
IC8031 or its peripheral circuit faulty.
Yes
No
Are there signals at pins (1) and (3) of
TC2 connector?
Q13, Q22 thru Q25 or their peripheral
parts faulty.
TC2 connector or output PWB faulty.
Checking the S-
VGA's blue video
circuit and its
peripheral circuits Checking the VGA's
blue video circuit
and its peripheral
circuits
Yes
No
Are there signals at VBB0 thru -7 of
IC8020?
Check the video
system's blue video
circuit and its
peripheral circuits.
D
D