Hitachi UX Twin Nozzle Service Manual page 325

6.5.2 Chipped print (upper dots)
Adjust the ink stream
position so that the ink
stream is centered with
respect to the gutter.
Since it is conceivable that the
ink flow path may be clogged,
replace the ink filter and MGV
filter, clean joints, backwash
the nozzle, and disassemble
and clean the nozzle.
Yes
Can normal
prints be made?
No
Replace the ink.
Sprinkle the makeup over
the deflection electrode to
clean it.
Adjust the charge voltage.
[Caution]
Do not repeat the nozzle backwash procedure more than two times.
If it is repeated in excess, the ink becomes thin, thereby
causing disordered prints.
If the ink is thin and printings become disordered, replace the ink.
Chipped print
Is the ink stream
No
positioned at the
center of the gutter?
Yes
Is the ink pressure
lower than the
specified limit?
No
Is it possible to make
normal prints with the
No
ink pressure raised
above the specified
limit?
Yes
Is there any ink or dirt
Yes
buildup on the plus
deflection electrode?
No
Is the ink stream
positioned at the center
of the charge electrode?
Yes
Is the charge
No
voltage properly
adjusted?
Yes
Resume the
operation.
Direction of
deflection
Yes
Can the ink pressure be
adjusted?
Provide pressure relief and
then replace the pressure-
reducing valve.
No
Adjust the ink
stream position.
6-83
Missing
dots
Yes
No
Adjust the ink
pressure until it is
within the limits.