Xerox ColorQube 9303 Series, Service Manual, Page: 1766 / 1812

February 2013
8-72 ColorQube® 9303 Family
Principles of Operation
Figure 19 Level detection
Mica Insulation Plates
Mica insulation plates surround the ink reservoir and help to maintain the ink reservoir temper-
atures. The plates provide excellent thermal qualities at a low cost but are fragile and are
therefore spared separately.
Air Pump
A rolling diaphragm air pump provides the air pressure required to:
• Supply ink to the printheads.
• Purge the printheads.
• Following a purge, provide low pressure assist until the printheads have been wiped by
the head maintenance (HM) assembly.
A manifold and a series of valves direct the air pressure to perform these functions. The sys-
tem contains twenty normally-vented three-way valves. Sixteen of the valves are used for ink
delivery and four for printhead maintenance. The air pump relies on pulse width modulation
(PWM) control to provide the correct flow rate for the varying functions.
The Low Pressure Assist (LPA) valve and the air pump are connected to an accumulator. The
LPA valve is a normally-open two way valve that closes when the system is required to
increase pressure for ink supply or a printhead purge, and opens, venting system pressure,
when ink supply or the purge is complete. To provide LPA, the pump shifts PWM values and
the LPA valve opens, dropping system pressure from approximately 4 psi to approximately
0.05 psi. The accumulator is a small plastic tank that houses an air filter and provides addi-
tional air volume rendering the purge and ink supply masses more robust to air leakage and
system variation.
Service Access
The ink reservoir is attached to the rear frame of the marking unit. It is held in place by two
screws and is removed by lifting the reservoir until the two locating pins clear the frame.
Remove the ink reservoir with the marking unit drawer fully extended.
Waste Tray
Waste Tray Detect Sensor
Refer to Figure 20 .
Figure 20 Waste tray detect sensor