Xerox ColorQube 9303 Series Service Manual page 1756

Figure 11.
Figure 11 Preheater plates and air supply
Heating of the media
In order to assure a good transfer of image from the drum to the media and to assure a good
bond of the ink, the media is pre-heated. This is accomplished by a large heating surface
below the lower paper path plate of the registration / preheat assembly. Air pressure forces the
paper to contact the heated lower metal plate. A loss of air pressure to the platelets will proba-
bly not result in jams but may contribute to lead edge mis-registration. Often the first indication
of an air pressure failure is missing pixels on side two of two-sided media. This is mainly
caused by insufficient heat since the paper is not being held fully against the heated plate.
Principles of Operation
Jam Clearance
If the machine jams and media is located in the registration / preheat assembly, the inboard
paper path drive motor will run in reverse until the stance sensor (at the rear) is actuated indi-
cating the registration / preheat assembly is in the '0' position. This is the position which will
allow the registration / preheat assembly to open. The outboard motor will then run in reverse
for a designated amount of time to open the registration / preheat assembly and to position the
heat shield (which hangs from the bottom of the horizontal paper path) in the open position.
The motor then maintains this open position. Two LEDs on the bottom of the heat shield will be
illuminated to help in jam clearance. To close the registration / preheat assembly, the front
motor will run very slowly in the forward direction to lower the registration / preheat assembly.
Jams may occur in the registration / preheat assembly if the scan bar senses more skew or lat-
eral movement than the registration / preheat assembly can rectify, resulting in a partial image
being left on the drum and / or transfix roller.
Drum Thermal Cutout
AC power to the drum heaters run through the thermal cutouts on the registration / preheat
assembly thermal cutout PWB. If the drum temperature is higher than the nominal operating
range (108 C), the thermal cutouts on the PWB open and interrupt AC power to the drum heat-
ers.
February 2013
8-62 ColorQube® 9303 Family