Iq15 Mottle Rap - Xerox DocuColor 2240 Service Manual

IQ15 Mottle RAP

This RAP troubleshoots the causes of output images showing image density that varies from
inboard to outboard edges, or randomly throughout the print.
Initial Actions
• Replace the paper in use with fresh, dry paper of the correct specification. Ensure that the
loaded media matches the UI or print driver settings.
• Determine if the Drum Cartridge or any of the Toner Cartridges are approaching end-of-
life. Replace if necessary.
• Perform Max Setup (ADJ 9.1). If this does not resolve the problem, continue with this
RAP.
• For DC 2240/1632 only: If mottle occurs mostly on heavyweight (HW1) or extra-heavy-
weight (HW2) paper stock, go to Table
use (HW1 and/or 2, Coated and/or Uncoated) and choose the applicable adjustment from
the table. If the problem persists, continue with this RAP.
Procedure
Enter dC612. Make a print of Test Pattern 22. The defect involves a single color.
Y N
The problem occurs with a specific type or weight of paper only.
Y N
Make a print of the Test Page. Open the Front Door when the lead edge of the print
begins to protrude from the Fuser Exit nip. Open the Fuser and examine the par-
tially-fused sheet. The defect is present in both the fused and unfused portion
of the sheet.
Y N
Clean or replace the Fuser
Enter dC612. Make a print of Test Pattern 22. As the print is being processed, open
the Front Door. Examine the image on the Transfer Belt. The image on the belt
has acceptable density.
Y N
Replace the Transfer Belt
Go to the IQ22 RAP to check 2nd BTR Backup Roll bias/contacts.
Clean/replace the 2nd BTR Assembly
If the problem continues, replace the Transfer Belt
Performing the adjustments in the following step may not eliminate mottle completely,
and/or may introduce other IQ problems; the intent is to reach the best compromise.
It may be possible to fine-tune the 2nd BTR transfer bias for a specific problem paper by
varying the secondary transfer remote for that paper.
The secondary transfer bias is a target value (based on temperature, humidity, 2nd BTR
resistance, and other Xerographic inputs) that represents what control logic has com-
puted to be the optimum transfer bias. Each paper type has an NVM location for remote
manual control of this target. The default for these "remote" locations is 100 (representing
100% of computed transfer bias target). The bias can be shifted from 0% to 200% of tar-
get.
A
Image Quality
IQ15
1. Verify with the customer what type of paper they
(PL 7.1).
(PL 5.3).
(PL 2.8).
(PL 5.3).
CAUTION
A
NOTE: If a paper type has a User IQ Default listed for it in Tables 2 or 3, ensure that the
customer has not changed the IQ setting before attempting this process; reset to the
default if necessary. Refer to Paper Tray Attributes in section 4 of the User Guide.
Refer to Table 2 (DC 2240/1632) or
for the affected paper type to 150. Adjust the remote up or down to achieve the best IQ
compromise. If the results are not satisfactory, set the remote value to 75 and adjust the
remote up or down to achieve the best IQ compromise.
Switch Drum Cartridges. The problem moves with the cartridge.
Y N
Check the following:
• Clean the HV contact for the developer in question.
• Replace the Toner Cartridge if not done previously.
• Replace the Developer (PL
ination. If the problem persists, replace the ATC Sensor
Replace the Drum Cartridge (see Machine Consumables
09/03
3-16
Table 3 (DC 3535). Change the value of the remote
6.2). Examine the housing for damage, wear, or contam-
(PL 6.2).
in Section 6).
DC 3535/2240/1632, WC M24
Initial issue