Hitachi UX Twin Nozzle Service Manual page 203

Symptom
The recovery
pump
malfunctions.
The solenoid
valve
malfunctions.
The recovery
route clogs.
No recovery
(Nozzle 2)
Sealing of the
recovery
route is
faulty.
Probable cause
Follow the same descriptions as those of "The supply pump
malfunctions ".
* MV23
malfunctions.
Clogging in the
recovery filter
Clogging in the
pipe or joint
The air is
sucked from
the connection
somewhere in
the recovery
route.
4-69
Check method
When "Open" is
executed on
"Solenoid
Valve/Pump Test"
screen, no operation
sound is produced.
A lot of foreign
materials stick on the
recovery filter.
Suck is performed
when the tube
connected to the
recovery filter is
removed.
Prepare the checking
tube which is made
by cutting PTFE tube
(Part name: PTFE
tube 2-3, Part No.:
451064) to the length
of about 600mm and
the beaker or the like
containing water.
Replace the tube
fixed to the Tube
Lock (1) on the main
ink tank with the
checking tube and
put the other end of
the checking tube
into the water. (Refer
to "4.2.2 Main Ink
Tank Replacement
Procedure".)
Block the gutter inlet
by hand wearing the
rubber glove or the
like and set both the
pump 2 and MV23 to
"Open" on Solenoid
Valve/Pump Test
screen. Check if the
air flows out from the
end of the checking
tube in water
continuously, i.e., if
the air is sucked from
the connection
somewhere in the
recovery route.
Repairing method
Replace or repair the
solenoid valve
(MV23). Refer to
"4.15 Repairing
method when the
circulation route is dry
or sticks".
Replace the recovery
filter.
Press makeup into
the end of the
recovery filter
connecting tube by
applying pressure
with a hand pump.
- Hand pump
specifications
Part name:
Nozzle cleaning
assembly
Part No.: 451000
If the air flows out
from the recovery
route, then change
the blocking position
to the downstream in
the recovery route
and find the place
where the air is
sucked in.
When the part in
question is found,
disconnect the part.
Remove foreign
materials if any and
reconnect the part.
When the fault is not
recovered, replace
the part.