Hitachi UX Twin Nozzle Service Manual page 200

Symptom
The supply pump malfunctions.
The solenoid
The ink
valve
pressure of
malfunctions.
Nozzle 2
does not
increase.
Others
The circulating
pump
malfunctions.
Backwash
is
impossible. The solenoid
(Nozzle 1)
valve
malfunctions.
The circulating
pump
malfunctions.
Backwash
is
impossible. The solenoid
(Nozzle 2) valve
malfunctions.
"Main Ink
The solenoid
Tank Too
valve
Full" often
malfunctions.
occurs.
Probable cause
* MV1
malfunctions.
* MV2
malfunctions.
* MV29
malfunctions.
The pressure
resistance of
MV6 is faulty.
* The pressure
sensor
malfunctions.
Follow the same descriptions as those of "The supply pump
malfunctions ".
* MV5
malfunctions.
Follow the same descriptions as those of "The supply pump
malfunctions ".
* MV25
malfunctions.
The pressure
resistance of MV7
is faulty.
The pressure
resistance of MV8
is faulty.
The pressure
resistance of
MV28 is faulty.
Check method
Follow the same descriptions as those of "Ink in
Nozzle 1 is not ejected".
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.
When "Open" is executed
on "Solenoid Valve/Pump
Test" screen, no operation
sound is produced.
When the pump 1 and
then MV1 are turned on,
ink flows to the recovery
tube. (Solenoid
Valve/Pump Test screen)
Ink ejects and printing can
be performed but the
pressure value is
abnormal.
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 makeup in the pipe
N is sucked even during
operation (except at
supply). (Remove the
tube connection block of
the makeup reservoir
and check.)
The makeup ejects from
Nozzle 1 and cannot be
stopped "at non-cleaning
stop".
The makeup ejects from
Nozzle 2 and cannot be
stopped "at non-cleaning
stop".
4-66
Repairing method
Replace or repair the
solenoid valve (MV1).
Refer to "4.15 Repairing
method when the
circulation route dry or
sticks".
Replace or repair the
solenoid valve (MV2).
Refer to "4.15 Repairing
method when the
circulation route dry or
sticks".
Replace the solenoid
valve (MV29).
Replace the solenoid
valve (MV6).
Replace the pressure
sensor. Refer to "4.6.2
Pressure Sensor (Nozzle
2) Replacement
Procedure".
Replace or repair the
solenoid valve (MV5).
Refer to "4.15
Repairing method
when the circulation
route is dry or sticks".
Replace or repair the
solenoid valve (MV5).
Refer to "4.15
Repairing method
when the circulation
route is dry or sticks".
Replace the solenoid
valve (MV7).
Replace the solenoid
valve (MV8).
Replace the solenoid
valve (MV28).