Xerox ColorQube 9303 Series Service Manual page 1757

Print Marking Unit and Drum Assembly
Marking Unit
The Marking Unit (MU) is composed of an enclosure (drawer) mounted on rails that allow the
MU to be pulled out from the IME for service. A fan and duct cools the electronics. The drawer
structure is composed of two injection molded plastic frames connected by sheet metal, which
is comprised of the MU frame mid-wall and MU frame floor. A MU Electronics Cover is remov-
able for servicing the MU electronics. Figure 1
Figure 1 Marking unit drawer
The drawer is mounted on full extension drawer slides, allowing it to be pulled out for service.
When the drawer is pushed back into the machine it registers to the chassis at four points, two
at the front and two at the back. The connection is made by two cylindrical protrusions moulded
into the front and two cylindrical holes moulded into the rear drawer frames that are mated with
features (extruded hole and raised pins) in the chassis. Once the drawer is pushed in and reg-
istered by the frame pins, fasteners are used to secure the drawer. Two fasteners are installed
near the front registration pins.
ColorQube® 9303 Family
illustrates the MU construction.
The MU includes the Staggered Full Width Array (SFWA) carriages that support the printheads
which deposit ink on the drum, the electronics to drive them and the Head maintenance sys-
tem. A series of linkages are employed to move the carriages between functional positions
using the drive mechanism on the back of the enclosure. The ink reservoir and valve manifold
are also attached to the back of the MU and the heated ink umbilicals run from the reservoir to
the carriages. Figure 2. The MU comprises the following components:
• Printheads
• Head Maintenance Wiper
• Waste Tray
• Umbilicals
• Carriages
• Ink Reservoir
• Carriage Drive
Figure 2 Marking unit components
The carriages register to the drum frame at three points. Three pins on each carriage, two pri-
mary pins front and back, are forced into contact with features on the drum frame and a third
secondary pin, is forced against an additional contact point to lock the carriage.
February 2013
8-63
Principles of Operation