Faults - No On-Screen Indications - Hitachi IJ PH Service Manual

6.5 Faults - No on-screen indications

6.5.1 Chipped print (lower dots)
Adjust the ink stream
position so that the ink
stream is centered with
respect to the gutter.
Replace the ink.
Pour the makeup ink
over the gutter edge
section to clean it.
Adjust the charge voltage.
CAUTION
1.
Ink/foreign
Print
matter
drop
2.
Gutter
Chipped print
Is the ink stream
No
positioned at the
center of the gutter?
Yes
Is the ink pressure
higher that the
specified limit?
No
Has the operating
Yes
time exceeded the ink
shelf life?
No
Is there ink or dirt
Yes
buildup on top of the
gutter edge section?
No
Is the charge
No
voltage properly
adjusted?
Yes
Resume the
operation.
If the ink stream is not centered with respect to the gutter,
dots having a small amount of deflection (lower dots of
characters) may collide against the gutter and fail to jet out
of the nozzle head, thereby causing chipped prints.
Position the ink stream at the center of the gutter.
If the ink pressure rises, the ink stream flow rate increases
to decrease the amount of deflection, causing dots having a
small amount of deflection to collide against the gutter and
producing chipped prints.
setting is within the specified limits.
6-43
Direction of
deflection
Yes
Can the ink pressure be
adjusted?
No
Provide pressure relief,
then replace the
pressure-reducing valve.
Ensure that the ink pressure
Missing dots
Yes
Adjust the ink
pressure until it is
within the limits.