Hitachi UX Twin Nozzle Service Manual page 284

6.2.27a (N1)Circulation Route Pressure Is High
< Occurrence condition of this alarm>
This alarm "Circulation Route Pressure Is High" is indicated when the ink pressure is NOT reduced
at MV5 opening step while the sequence ①, ② or ③ below is executed and the ink is being ejected.
① Ink Eject Sequence A
② Ink Eject Sequence B
③ Ink Circulation Sequence
Circulation Route
Pressure Is High
Does the MV5 operate?
Yes
Press "Nozzle backwash1" button and then
"Start/Continue" button on Circulation Control
screen and sprinkle makeup over the tip of the
nozzle.
Is makeup suctioned?
Press "Operation test" button of "Viscometer calibration"
screen and confirm that ink flows to the viscometer from
the Main ink tank.
Does ink flow to the
viscometer from the Main
ink tank?
No
Replace the circulation pump.
No
Replace MV5 or clean any ink buildup or
other foreign matters.
Yes
Yes
No
Yes
6-42
Does the fault recur?
No
(*1)： When you replace the printhead, refer to
"4.13 Print Head Replacement
Procedure".
[Caution]
Be sure to check that there is no wrong
connection
[Connector numbers and Identifying method of
harnesses]
Diagram".
Does the fault recur?
No
Resume the
operation.
of harnesses by referring
"3.3.20 Electrical Connection
in
Yes
Replace the print head*1.
to