HP Color LaserJet CP2020 Service Manual - Page 206

Problem-solve diagrams ● Repetitive image defects ● Interface ports ● DC controller PCA ● Major components ● Solenoids, clutches, and sensors ● Rollers ● Motors and fans ● PCAs ● Timing diagram ● Circuit diagram Repetitive image defects If the product output has a consistent, repetitive defect, use the table in this section to determine which part needs to be replaced based on the measured distance between the repetitions of the defect. Repetitive defects caused by the ITB normally appear on every other page, because the ITB is longer than a page. However, the period of the repetitive defect can vary depending on the type of media, and a repetitive defect can occur more than once on the same page. NOTE: The following table replaces the graphical repetitive defect ruler. You can make your own ruler by using these measurements. Table 7-1 Repetitive image defects Distance between identical defects Component About 22.0 mm (0.86 in) Developer roller (one rotation) About 38.0 mm (1.49 in) Primary charging roller About 44.0 mm (1.73 in) Registration roller About 58.0 mm (2.28 in) Secondary transfer roller or Fuser sleeve About 63.0 mm (2.48 in) Pressure roller About 75.0 mm (2.95 in) Photosensitive drum About 78.0 mm (3.07 in) ITB (ITB drive roller or secondary transfer opposed roller) 186 Chapter 7 Problem solve ENWW