Troubleshooting Procedure For The Circulation System - Hitachi UX Twin Nozzle Service Manual

4.14 Troubleshooting Procedure for the Circulation System

Perform "(1) Fault locating and repairing method" for each trouble symptom.
For the items marked * in "Probable Cause", perform "(2) Fault locating method for the control
system/circulation system" to make sure that the control system is normal, and then perform the repair
work.
(1) Fault locating and repairing method
Trouble
symptom
Ink in
Nozzle 1 is
not
ejected.
Probable cause
* The motor
malfunctions.
The drive cam is
damaged.
The follow
operation of the
The supply stroke is faulty.
pump
Foreign
malfunctions.
materials are
mixed in the
check valve.
The check valve
is dry or sticks.
* MV1
malfunctions.
The solenoid
valve
malfunctions.
* MV9
malfunctions.
Clogging in the
pipe or joint.
The supply
route clogs.
Clogging in the
orifice plate.
Check method
The motor does not
rotate.
A crack or powder
abrasion is found on
the cam.
The piston cannot
follow the cam motion.
The solenoid valve is
operated but charging
and drainage are not
completed within the
specified time.
The solenoid valve is
operating but ink does
not flow.
When "Open" is
executed on "Solenoid
Valve/Pump Test"
screen, no operation
sound is produced.
When "Open" is
executed on "Solenoid
Valve/Pump Test"
screen, no operation
sound is produced.
The operation sound of
MV1 and MV9 is
produced, but ink does
not flow.
When backwash
conducted, makeup
does not flow to the
tube of circulation
route.
4-63
Repairing method
Replace the motor.
Replace drive unit.
Replace supply pump
head.
When the fault is not
recovered by repeating
"startup" and "shutdown",
replace the supply pump
head.
Refer to "4.15 Repairing
method when the
circulation route is dry or
sticks".
Replace or repair the
solenoid valve (MV1).
Refer to "4.15 Repairing
method when the
circulation route is dry or
sticks".
Replace the solenoid
valve (MV9).
Refer to "4.15 Repairing
method when the
circulation route is dry or
sticks".
Clean the orifice plate
with ultrasonic cleaning.