Pq 3 Bands; Pq 4 Black Lines - Xerox 8850 Service Manual

PQ 3 Bands

Table 1 Bands Symptom / Check
Symptom/ check Probable Cause
Bands are 1 mm or more and
are perpendicular to the
media feed direction. High
density bands are called black
lines.
1. Defective or intermittent
Charge Scorotron.
2. Defective Detack Corotron. 2A. Check / replace the
3. Poor cleaning
4. Defective or contaminated
Drum.
5. Damaged or incorrectly
installed Drum Encoder.
Drum Drive Motor
8850/ 510DP

PQ 4 Black Lines

Corrective Action Symptom/ check
Black lines appear in the
direction of media feed.
1A. Check / clean / replace
the connections to the Charge
Scorotron (PL 9.3).
1B. Perform Electrostatic
Series (ADJ 9.2).
Detack Corotron. (REP 9.9).
2B. Ensure that the Corotron
is installed in the correct posi-
tion.
3. Replace the Cleaner Blade
(REP 9.4).
4A. Wash the Drum (GP 3
Drum Maintenance)
4B. Determine and fix the
cause of the damage to the
Drum. Replace the Drum
(REP 9.3).
5. Check that the Encoder is
installed correctly (REP 9.23)
Replace the Encoder or Drum
Drive Motor (PL 9.1)
03/2003
3-11
Table 1 Black Lines Symptom / Check
Probable Cause Corrective Action
1. Developer Bias and Detack 1A. Clean/Replace the Detack
Corotron voltage set incor- Corotron
rectly 1B.
Series
2. Contaminated, damaged 2. Clean/replace or check the
or disconnected Charge connections to the charge
Scorotron scorotron
3. Poor cleaning 3. Replace the Cleaner Blade
(REP
4. The surface of the Heat/ 4. Determine and fix the
Pressure Roll(s) is damaged. cause of the damage to the
Rolls. Replace the rolls
10.2,
5. The Drum surface is con- 5. Determine and fix the
taminated or damaged. cause of the damage to the
Drum.
(REP
6. The fuser temperature is 6. Adjust the Fuser tempera-
too high. ture
7. Contaminated or damaged 7. Check for foreign objects
mag roll. on the mag roll.
8. Defective Detack Corotron. 8. Check / replace the
Detack Corotron.
(PL 8.3).
Perform Electrostatic
(ADJ 9.2).
(PL 9.3).
9.4).
(REP
REP 10.8).
Replace the Drum
9.3).
(ADJ 10.1)
(PL 8.3).
Print Quality
PQ 3, PQ 4