Print Quality Raps; Pq 1 Background; Pq 2 Dark Bands - Xerox 8850 Service Manual

PQ 1 Background

Table 1 Background Symptom / Check
Symptom / check Probable Cause
Contamination of the blank
area by toner particles on the
print
1. An incorrect electrostatic
value
2. Developer Bias incorrect.
3. Toner concentration too
high.
4. Erase Bar operation.
5. Defective Cleaner Blade
6. Web Oil system not operat-
ing correctly.
7. Contaminated or defective
Drum.
9. Site environment is hot and
humid.
Print Quality
PQ 1, PQ 2

PQ 2 Dark Bands

Corrective Action Symptom/ checks
Bands are 1 mm or more wide
and are in the media feed
direction. High density bands
are called black lines.
1A. Perform Electrostatic
Series (ADJ 9.2).
1B. Perform GP 1 Xero-
graphic HVPS Checkout Pro-
cedure.
1C. Clean/Replace/Repair
the corotrons.
2A. Perform Electrostatic
Series (ADJ 9.2).
2B. Perform GP 1 Xero-
graphic HVPS Checkout Pro-
cedure.
3. Perform Image Density
(ADJ 9.3).
4. Refer to BSD 9.6 and
check for correct operation of
the Erase Bar.
6. Replace the Cleaner Blade
(REP 9.4).
7. Refer to BSD 10.2 and
check Web Oil system for cor-
rect operation.
8. Replace the Drum (REP
9.3).
9A. Install Developer Heater
Kit
9B. Perform General Proce-
dure GP 8 Toner Control Sys-
tem Calibration and set for
humidity greater than 65%.
03/2003
3-10
Table 1 Bands Symptom / Check
Probable Cause Corrective Action
1. Contaminated charge 1. Clean / replace screen /
scorotron pins (REP
Detack Corotron contami-
nated.
2. Defective Cleaner Blade 2. Replace the Cleaner Blade
(REP 9.4).
3. Contaminated magnetic 3. Check for foreign objects
roll. on the mag roll.
4. Incorrect Electrostatic 4B.
value. Series
4C.
graphic HVPS Checkout Pro-
cedure.
5. Toner cloud from the Devel- 5A. Ensure that the Pressure
oper Module contaminating Equalizer Tubes are clean
the Drum and corotrons. (REP 9.18).
5B. Check for toner buildup on
the lower edge of the Devel-
oper Housing.
5C. Check that the Toner Dust
Trap, Tubes are not plugged.
Replace
9.10).
5D. Check/Replace the Toner
Filter (PL
6. Contaminated or defective 7. Replace the Drum
Drum. 9.3).
7. Image Module LEDs oper- 8. Enter [9-21-5] and check for
ating incorrectly. correct operation.
BSD 6.1
electrical connections to/from
the Receiver PWB and the
LED Image Bar).
8. Photoreceptor Drive Motor Check at the Encoder is
Encoder not installed or oper- installed correctly
ating correctly. Replace the Encoder
9.8).
Perform Electrostatic
(ADJ 9.2).
Perform GP 1 Xero-
as required (PL
9.10).
(REP
(Refer to
and check for correct
(REP 9.23).
(PL 9.1).
8850/ 510DP