Hitachi UX Twin Nozzle Service Manual page 316

6.4.13a (N1) Ink Pressure Low
(N1) Ink Pressure Low
Confirm the indicated value and standard value of ink
pressure in Nozzle1 on "Operation management" screen.
The indicated value of ink pressure
No
in Nozzle1 exceeds the lower limit?
(Standard value x 0.90 >Indicated value)
Is the difference of ±0.01MPa
or more in indicated value of
ink pressure between Nozzle1
and Nozzle2?
Do MV1 and 2 operate?
Replace or repair the troubled
solenoid.
Does ink flow into main ink tank
when pumps MV1 & MV6 are
operated?
Replace or repair the
supply pump.
Can the pressure be adjusted by
the pressure reducing valve?
Yes
Adjust the pressure to
standard value
by the pressure reducing
valve.
Is the warning released?
Resume the operation.
Yes
Yes
No
Yes
No
Yes
No
No
Yes
Yes
No
Yes
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(*1): When you replace pressure reducing valve, refer to "4.3
Pressure Reducing Valve Replacement Procedure".
(*2): When you replace pressure sensor1, refer to "4.6.1
Pressure Sensor (Nozzle 1) Replacement Procedure".
Does MV9 operate?
No
Replace or repair the troubled
solenoid.
Replace MGV filter in Nozzle1.
Replace ink filter.
Can the pressure be adjusted by
the pressure reducing valve?
No
Replace the pressure reducing valve.*1
Can the pressure be adjusted by
the pressure reducing valve?
No
Replace the pressure sensor1.*2
Yes