HP Color LaserJet Enterprise CM4540 Service Manual - Page 668

Problem Vertical white lines appear in a particular color. Sample Vertical white lines appear in all colors. Horizontal lines appear on the page. A horizontal white line appears on the page. Cause Solution The laser beam window is dirty. Remove the affected print cartridge and reinstall it. The PGCs will clean the glass. Scratches are present on the circumference of the developing cylinder or photosensitive drum. White scratch down the page could mean the scanner glass needs to be cleaned. Remove the affected print cartridge and reinstall it. The PGCs will clean the glass. If the problem persists, replace the affected print cartridge. The laser/scanner-unit mirror is dirty. Replace the laser/scanner assembly. See Laser/scanner assembly (Y/M) on page 275 or Laser/scanner assembly (C/Bk) on page 279. Horizontal scratches on the fuser roller. Replace the fuser. See Fuser on page 112. Scratches are present on the circumference of the ITB. White scratch down the page could mean the scanner glass needs to be cleaned. Remove the affected print cartridge and reinstall it. The PGCs will clean the glass. Replace the ITB. See Intermediate transfer belt (ITB) on page 120. Repetitive horizontal lines appear. Use the repetitive defects ruler to identify the dirty roller. Clean the roller. If the roller cannot be cleaned, replace the fuser. See Fuser on page 112. Horizontal scratches are present on the photosensitive drum. Replace the print cartridge of the color that matches the defect. Horizontal scratches are present on the fuser roller. Replace the fuser. See Fuser on page 112. Repetitive horizontal white lines appear. Use the repetitive defects ruler to identify the dirty roller. Clean the roller. If the roller cannot be cleaned, replace the roller. Horizontal scratches are present on the photosensitive drum. Replace the print cartridge of the color that matches the defect. Scratches are present on the circumference of the ITB. Replace the ITB. See Intermediate transfer belt (ITB) on page 120. 616 Chapter 3 Solve problems ENWW