HP Indigo W7200 Charge Roller -- CA393-00080 Rev 07 - Page 6

b. Make sure that the guide rails are not loose. Figure 1-4 Charge roller housing 1 Guide rails 2 Front position pins 7. Verify that the charge roller housing rests completely on the three position pins on the press wall. 8. Make sure that the charge roller housing holding screws allow the charge roller to move to the fully engaged position. Troubleshooting dirt accumulation on the roller It explains how to troubleshoot the dirt accumulation on the roller. Overview During the charge roller operation, it is in full contact with the PIP foil. As a result, it can collect ink particles that were not removed by the cleaning station. In addition, the high voltage purple light that charges the PIP generates a very high localized temperature at the charging point. This condenses imaging oil fumes into a sticky residue on the balancing and charge rollers. After several impressions, this sticky residue accumulates enough dirt to affect the PIP charge and cause print quality defects. The print quality defect looks like thin dark stripes on the print. Figure 1-5 Sticky residue and dirt Figure 1-6 Sticky residue and dirt 4 Chapter 1 Procedures