Figure A-20. Displays Scrambled Or Missing Segments - Wayne Dresser Vista 1 Series Service Manual

Display scrambled,
missing segments,
or display appears
normal but frozen.
Does
problem exist on
both sides of
dispenser ?
Is there
a jumper wire
across pins 8 & 9 of
J5 connector on the
Cash/credit
interface
board ?
Reseat connector to J2 on
cash/credit interface board
and connector to J4 or J5
on computer assembly.
J4 is for side 1 display.
Check this cable for continuity
and replace it if defective.
problem
corrected ?
Check F1 fuse on
cash/credit interface board.
If fuse is open replace the
board. If dispenser is not
Push-to-Start model, the
board shoud be replaced
since F1 does not exist.
Replace the
computer assembly.
problem
corrected ?

FIGURE A-20. DISPLAYS SCRAMBLED OR MISSING SEGMENTS.

February 1997
Do displays
YES
appear normal but
frozen ?
NO
NO
NO
YES Replace
this
wiring
harness.
Is the
NO
problem
corrected ?
Is the
YES
NO
Is the
problem
corrected ?
NO
Replace the display
board.
Is the
problem
NO
corrected ?
Replace cash/credit
Is the
interface board
NO
if not replaced in
step above.
YES
Replace F3 on the
computer assembly.
After replacing,
YES
verify that new F3
is still good.
YES
YES
YES
Is the
NO
problem
corrected ?
YES
END
Is the
problem
YES
corrected ?
NO
Replace
computer
assembly.
Replace cable
between J1 on
cash/credit interface
board and J1 on
display board.
Part No. 920160 Rev A
93