Troubleshooting Procedure For The Circulation System - Hitachi IJ PH Service Manual

4.11 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) 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
Probable cause
symptom
The supply
pump
malfunctions
.
Ink does
not jet.
The
solenoid
valve
malfunctions
.
The supply
route clogs.
The makeup
ink pump
malfunctions
Makeup .
ink does
The
not
solenoid
circulate.
valve
malfunctions
.
Status check
* The motor The motor does not
malfunctions. rotate.
A crack or friction
The drive cam
powder is found on
is damaged.
the cam.
The follow The piston cannot
operation of the follow the cam
stroke is faulty. motion.
The solenoid valve
Foreign is operated but
materials are charging and
mixed in the discard are not
check valve. completed within the
specified time.
The solenoid valve
The check
is operated but ink
valve is dry or
does not flow.
sticks.
When "Open" is
executed on the
Solenoid
* MV1
Valve/Pump Test
malfunctions.
screen, no operation
sound is produced.
When "Open" is
executed on the
* MV9 Solenoid
malfunctions. Valve/Pump Test
screen, no operation
sound is produced.
The operation sound
Clogging in the of MV1 and MV9 is
pipe or joint. produced, but ink
does not flow.
When backwash
practice, makeup ink
Clogging in the
does not flow to the
orifice plate.
tube of circulation
route.
The same as "The supply pump malfunctions".
When "Open" is
executed on the
* MV8 Solenoid
malfunctions. Valve/Pump Test
screen, no operation
sound is produced.
4-25
Repairing method
Replace the motor.
Replace the pump
unit.
Replace the pump
unit.
If this trouble cannot
be repaired by
repeating the
operation and stop,
replace the pump
unit.
Refer to "4.12
Repairing method
when the circulation
route dry or sticks".
Replace or repair the
solenoid valve
(MV1). Refer to
"4.12 Repairing
method when the
circulation route dry
or sticks".
Replace the solenoid
valve (MV9).
Refer to "4.12
Repairing method
when the circulation
route dry or sticks".
Clean the orifice
plate with ultrasonic
cleaning.
Replace the solenoid
valve (MV8).