Hitachi IJ RX2, Service Manual

Page: 226 / 252

6-47
6.5 Faults - No on-screen indications
6.5.1 Chipped print (lower dots)
CAUTION
1. 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.
2. 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. Ensure that the ink pressure
setting is within the specified limits.
Direction of
deflection
Missing dots
Gutter
Ink/foreign
matter
Print
drop
Chipped print
Replace the ink.
Adjust the ink stream
position so that the ink
stream is centered with
respect to the gutter.
No
Is the ink stream
positioned at the
center of the gutter?
Yes
Is the ink pressure
higher that the
specified limit?
No
Yes
Has the operating
time exceeded the ink
shelf life?
No
Yes
Resume the
operation.
Pour the makeup
over the gutter edge
section to clean it.
Is there ink or dirt
buildup on top of the
gutter edge section?
Yes
No
Adjust the charge voltage. Yes
Is the charge
voltage properly
adjusted?
No
Adjust the ink
pressure until it is
within the limits.
Can the ink pressure be
adjusted?
No
Yes
Provide pressure relief,
then replace the
pressure-reducing valve.