Hitachi UX Twin Nozzle Service Manual page 331

6.5.8a (N1) No ink ejection from nozzle1
Yes
Execute the "Nozzle
Backwash1" function.
Yes
Is the problem
fixed?
No
Remove the orifice plate
from the nozzle, subject it
to ultrasonic cleaning, and
put it back on the nozzle.
Yes
Is the problem
fixed?
No
Does shutoff valve
MV9 operate?
No
Is there the conduction
of the fuse [FR2] of the
EZJ125 board?
No
Replace the
EZJ125 board.*1
Replace shutoff
valve MV9.
Yes
Is the problem
fixed?
No
Replace the circulation unit.
[Caution]
Resume the
1. Do not repeat the nozzle backwash procedure more than two times.
operation.
If it is repeated in excess, the ink becomes thin, thereby causing
disordered prints.backwash
2. If the ink is thin and printings become disordered, replace the ink.
No ink ejection
from nozzle1
Is ink pressure of
No
nozzle1 set to the value
specified?
Is the pump
motor running?
Is the Ink flowing
from the Ink filter "C"
motor running?
Replace the ink filter.
Yes
Is the problem
fixed?
Is the Ink flowing from
the Reducing valve "C"
running?
Yes
Replace the pressure-
reducing valve.
Yes
Is the problem
fixed?
No
Is MV1 and 2
sticking?
Repair the troubled
solenoid.
Replace the MV1 and 2
6-89
(*1): When you
[Replacement procedures of EZJ125 board] in "3.3.5
EZJ125 board (Nozzle1 drive board)".
(*2): When you
[Replacement procedures of EZJ133 board] in "3.3.1
EZJ133 board (MPU board)".
[Caution]
Be sure to check that there is no wrong connection of
harnesses by referring to [Connector numbers and
Identifying method of harnesses] in "3.3.20 Electrical
No
Connection Diagram".
Yes
Is the EZJ133 board
CN13 connector,
Yes
EZJ138 board CN1, 3,
4 and 6 connector, or
pump motor connector
No
disconnected?
No
Yes
No
Connect any
disconnected connector.
Yes
Is the problem
No
fixed?
No
Replace the
Yes
EZJ133 board.*2
Yes
Is the problem
fixed?
Replace the
circulation unit.
replace EZJ125 board,
replace EZJ133 board,
No
Is the connection
harness conducting?
Yes
No
Replace the connection
harness.
Is the problem
fixed?
No
No
refer to
refer to
Yes
Yes