Hitachi UX Twin Nozzle Service Manual page 327

6.5.4 Increased character distortion
Optimize the clearance
between the nozzle head
end and print target.
Replace the ink.
No
Adjust the excitation
voltage and pressure to
ensure proper ink drops
generation.
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 Are normal
prints obtained?
No
Replace the ink.
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.
Increased character
distortion
Is optimum clearance
provided between the
No
nozzle head end and print
target?
Yes
Is the ink pressure
higher than the
specified limit?
No
Has the operating
Yes
time exceeded the ink
shelf life?
No
Are ink drops
properly generated?
Yes
Is the normal height
Yes
obtained when the ink
pressure is raised above
the specified limit?
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.
Yes
Can the ink pressure
be adjusted?
No
Provide pressure relief and
then replace the pressure-
reducing valve.
No
Adjust the ink
stream position.
6-85
Yes
Adjust the ink
pressure until it is
within the limits.