Xerox 8850 Service Manual

03/2003
3-18
8850/ 510DP
PQ 17, PQ 17A
Print Quality
PQ 17 Smears PQ 17A Smudge
Table 1 Smears Symptom / Check
Symptom/ check
Areas of the image on the
print are blurred. This
occurs at the image transfer
area and is caused by a dif-
ference of speed between
the Drum and the media.
Location of Smear Probable Cause Corrective Action
20 - 25 mm from the
Lead Edge of the
print
Media Guides miss-
ing or incorrectly
installed.
Check / replace (PL
9.4)
Random smears BTR Drive Gears
worn, contami-
nated or broken.
Check and clean
BTR Drive Gears.
Replace if broken.
(REP 9.22).
106 - 126 mm from
the Lead Edge of
the print
Worn (smooth)
Fuser Heat Roll (PL
10.2)
Check / replace
(REP 10.2)
140 - 160 mm from
the Trail Edge of
the print
Cutter Check for loose
Cutter Drive Pulley,
Shim / replace (PL
7.8)
Table 1 Smudge Symptom / Check
Symptom/ check
A smudge is a displacement
of the toner image on the
Drum or the media.
Location of
Smudge
Probable Cause Corrective Action
Perform GP 2, Image on
Drum to determine if the
Smudge occurs on the
media or the Drum.
Media Fuser Heat Roll Check for a worn
(smooth) Fuser
Heat Roll. Replace
(REP 10.2)
Media Pressure Roll Check for a worn/
contaminated Pres-
sure Roll. (REP
10.8)
Media Excessive media
curl (smudge
appears 100 mm
from lead or trail
edge)
Ask the customer to
replace the media.
Media Detack Corotron Check for contami-
nation or signs of
arcing. Clean /
replace (PL 9.4)
Vellum Smudge is a special
defect that exhibits marginal
fusing fix. Toner can chip off
of the media and horizontal
lines are broken (image dis-
placement).
Combination of Vellum beam strength
and low Fuser Heat Roll drive force. (The
media is flexible enough that it buckles
during fusing. The toner then melts and
partially sticks to the Fuser Heat Roll.
The image is displaced in front of it’s cor-
rect position. The toner can also
become a clump on the media and easily
chip off of the media.)
Replace the Fuser
Heat Roll and/ or
Pressure Roll (REP
10.2, REP 10.8).
Drum Mechanical interfer-
ence with the image
on the Drum
Check for interfer-
ence.
Drum Buildup of devel-
oper material on the
lower extrusion of
the developer hous-
ing rubbing the
developed image
on the Drum.
Push excess devel-
oper material back
into the housing.

Xerox 8850 Specifications

General

Brand	Xerox
Model	8850
Category	Printer
Language	English