Hitachi PB - Troubleshooting Procedure for the Circulation System

4-21
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.
①Fault locating and repairing method
Trouble
symptom
Probable cause Status check Repairing method
* The motor
malfunctions.
The motor does not
rotate.
Replace the motor.
The drive cam is
damaged.
A crack or friction
powder is found on
the cam.
Replace the pump unit.
The follow
operation of the
stroke is faulty.
The piston cannot
follow the cam
motion.
Replace the pump unit.
Foreign
materials are
mixed in the
check valve.
The solenoid valve is
operated but charging
and discard are not
completed within the
specified time.
If this trouble cannot
be repaired by
repeating the
operation and stop,
replace the pump unit.
The supply
pump
malfunctions
.
The check valve
is try or sticks.
The solenoid valve is
operated but ink does
not flow.
Refer to “4.12
Repairing method
when the circulation
route dry or sticks”.
※MV1
malfunctions.
When “Release” is
executed on the
Solenoid Valve/Pump
Test screen, no
operation sound is
produced.
Replace or repair the
solenoid valve (MV1).
Refer to “4.12
Repairing method
when the circulation
route dry or sticks”.
※MV2
malfunctions.
When “Release” is
executed on the
Solenoid Valve/Pump
Test screen, no
operation sound is
produced.
Replace or repair the
solenoid valve (MV2).
Refer to “4.12
Repairing method
when the circulation
route dry or sticks”.
※MV9
malfunctions.
When “Release” is
executed on the
Solenoid Valve/Pump
Test screen, no
operation sound is
produced.
Replace the solenoid
valve (MV9).
The solenoid
valve
malfunctions
.
The pressure
resistance of
MV6 is faulty.
When the pump and
then MV1 are turned
on, ink flows to the
collation tube.
(Solenoid Valve/Pump
Test screen)
Replace the solenoid
valve (MV6).
The ink
pressure
does not
increase.
Others
※The pressure
guage
malfunctions.
･Ink jets and printing
can be performed but
the pressure value is
abnormal.
Replace the pressure
guage.
The makeup
ink pump
malfunctions
.
The same as “Ink does not jet".
Makeup
ink does
not
circulate.
The solenoid
valve
malfunctions
.
※MV8
malfunctions.
When “Release” is
executed on the
Solenoid Valve/Pump
Test screen, no
operation sound is
produced.
Replace the solenoid
valve (MV8).