Sharp XG-P25X Service Manual page 47

TROUBLE SHOOTING TABLE FOR PC I/F UNIT
Checking the GA4 and its
peripheral parts
Select R, G and B individually
from the process mode
pattern menu.
Are the R, G and B video
output signals as specified?
Measure the signals at
FB8004, FB8005 and
FB8006 on the oscilloscope
screen.
Are the signals selected on
the pattern menu and those
being measured just the
same?
Are there clock signals at
pins (31), (32) and (33) of
IC8051?
Measure the signals at
TL8106, TL8107, TL8108,
TL8109, TL8110 and TL8111
on the oscilloscope screen.
Are the signals selected on
the pattern menu and those
being measured just the
same?
IC8029 defective.
YES
NO
GA4 checking ended.
YES
NO
Output PWB defective.
NO
YES
Is there the 32.5-MHz
clock signal at
TP8114?
Is there the 32.5-MHz
clock signal at
FB8110?
IC8025 defective.
NO
YES
IC8025 defective.
49
YES
NO
IC8029 defective.
NO
X8005 defective.
YES
XG-P25X
(Continued)