Canon iR C6800 Series Service Manual page 917

Chapter 13
13.3.2.5.4 White Spots at 51mm Intervals
0005-6903
Cause
White spots can occur when wear starts on the primary transfer roller (i.e., an area of the roller is likely to become
soft).
Field Remedy
1. Replace the primary transfer roller.
2. Clean the rollers inside the ITB unit and the scraper inside the intermediate transfer belt.
<Cleaning the Rollers Inside the ITB Unit and the Scraper Inside the Intermediate Transfer Belt>
1) Dry wipe the rollers [1] and the scraper [2] shown in the following figure with lint free paper.
[1]
[2]
F-13-30
Description
The white spot in question tends to occur at intervals of about 51 mm.
13-45