HP Color LaserJet Managed E75245

Review the following information about a repetitive image defect ruler.

When troubleshooting the source of some print image defects, one solution is to identify if it is a repetitive defect (does the print quality defect appear multiple times on the printed page?). If this is the case, use a ruler to measure occurrences of repetitive image defects to help solve image-quality problems. For more information, see Using a ruler to measure between repetitive defects.

Use a ruler to measure occurrences of repetitive image defects to help solve image-quality problems. Place the ruler next to the first occurrence of the defect on the page. Find the distance between identical defects and use the table below to identify the component that is causing the defect.

IMPORTANT:
Do not use solvents or oils to clean rollers. Instead, rub the roller with a lint-free cloth. If dirt is difficult to remove, rub the roller with a lint-free cloth that has been dampened with water.

NOTE:
Defects on the tray pickup rollers or the Tray 1 pickup roller do not cause a repetitive defect. Defects on these rollers cause a defect to appear only on the leading edge of the image.

TIP:
To make a printer specific repetitive defect ruler, use a metric ruler to transfer the measurements in the table below to a transparency or the edge of a piece of paper—clearly label each ruler mark with the associated defective assembly.

NOTE:
The primary charging roller, photosensitive drum, and developer roller cannot be cleaned because they are internal assemblies in the toner cartridge or imaging drum. If one of these assemblies is causing the defect, replace the toner cartridge or the imaging drum.

Assembly	Distance between defects
Developer roller	26 mm (1.02 in)
Primary charging roller	34 mm (1.34 in)
Photosensitive drum	94 mm (3.70 in)
Registration roller	42 mm (1.65 in)
Secondary transfer roller	56 mm (2.20 in)
Fuser film	77 mm (3.03 in)
Pressure roller	83 mm (3.27 in)

Use a ruler to measure between repetitive defects

1. Identify a repetitive defect on the page.
   TIP: Print a cleaning page to see if that resolves the defect.
   NOTE: Some printers allow loading Letter and A4 media in short-edge-first or long-edge-first orientation in the paper trays. When measuring repetitive defects, make sure to place the ruler at the leading edge of the page. This is the edge of the page that feeds into the printer first.
   types of repetitive defects.
   • Lines
   • Smudges
   • Dots or spots
2. Position a metric ruler on the page with the “zero” ruler mark at one occurrence of the defect
3. Locate the next occurrence of the defect
4. Measure the distance (in millimeters) between the two occurrences (callout 1), and then use the Repetitive defects table to determine the defective assembly.
   TIP: Always measure from and to the same point on the defects. For example, if the ruler is “zeroed” at the top edge of a defect, measure to the top edge of the next occurrence of that defect.