HP LaserJet Pro 300 HP LaserJet Pro 300 and 400 Color M351 and M451 - Software - Page 187

Print troubleshooting Print-quality troubleshooting tools Repetitive image defects ruler If the product output has a consistent, repetitive defect, then use the table in this section to determine which part needs to be cleaned or replaced based on the measured distance between the repetitions of the defect. NOTE: Spots can be dark or white (dropouts), bands can be all shapes and sizes. Component Distance between defects (mm) Type of defects Developing roller1 About 22 Dropouts Dark, sharp bands Primary charging roller1 About 26 Dropouts RS roller About 29 Dropouts Secondary transfer roller About 47 Dropouts Dirt on the back of page Fuser film About 58 Dropouts Dirt on page Loose toner Pressure roller About 63 Dirt on page Dirt on the back of page Loose toner ITB drive roller About 76 Spots Photosensitive drum1 About 95 Dropouts Dirt on page 1 The primary charging roller, photosensitive drum, and developing drum cannot be cleaned. If these rollers cause a repetitive defect, replace the corresponding cartridge, either the imaging-drum cartridge, or developing cartridge. Calibrate the product 1. Use the arrow buttons to select the System Setup menu, and then press the OK button. 2. Use the arrow buttons to select the Print Quality menu, and then press the OK button. 3. Use the arrow buttons to select the Calibrate Color item, and then press the OK button. 4. When the display shows the Calibrate Now message, and press the OK button. ENWW Print troubleshooting 171