Hitachi IJ UX Service Manual page 279

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.
Yes
Since it is conceivable that the
ink flow path may be clogged,
clean the ink final filter and
joints, backwash the nozzle,
and disassemble and clean the
nozzle.
Yes
Are normal
prints obtained?
No
Replace the ink.
Adjust the charge voltage.
NOTICE
Do not repeat the nozzle backwash procedure more than two times.
If it is repeated to an excess, the ink becomes thin, thereby causing
disordered prints. If the ink is thin and disordered prints are encountered,
replace the ink.
Increased character
distortion
Is optimum clearance
No provided between the
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
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.
6-61
Yes
Can the ink pressure
be adjusted?
No
Provide pressure relief and
then replace the pressure-
reducing valve.
Adjust the ink
pressure until it is
within the limits.
No
Adjust the ink
stream position.
Yes