HP Color LaserJet Enterprise CP4020 Service Manual - Page 443

Problem The page is all black or a solid color. Sample Cause Poor contact exists in the primary charging bias or developing bias contacts between the print cartridge and the product. Solution Clean each contact of the color that produces the all black or solid color. If the problem remains after cleaning, check the contacts for damage. Replace any deformed or damaged parts. Replace the affected print cartridge. White spots appear in an image The back of the page is dirty. Vertical streaks or bands appear on the page. The primary transfer roller is Replace the ITB. See Intermediate deformed or has deteriorated. transfer belt (ITB) on page 92. The secondary transfer roller is deformed or has deteriorated. Replace the secondary-transferroller. See Secondary transfer roller on page 90. The secondary transfer roller is dirty. Replace the secondary transfer roller. See Secondary transfer roller on page 90. The fuser inlet guide or separation guide is dirty. Clean the dirty parts. If the dirt does not come off, replace the guide. The pressure roller is dirty. Run the cleaning page several times. If the dirt does not come off, send a fuser cleaning kit. If the issue persists, replace the fuser. See Fuser on page 85. Scratches are present on the circumference of the photosensitive drum. Replace the print cartridge of the color that matches the defect. Scratches are present on the circumference of the fuser roller. Replace the fuser. See Fuser on page 85. Scratches are present on the Replace the ITB. See Intermediate circumference of the ITB. transfer belt (ITB) on page 92. The ITB drive roller is deformed or has deteriorated. The ITB cleaning mechanism is malfunctioning. ENWW Solve image-quality problems 411