When a piece of paper passes through the printer, the 12 rollers in the machine turn more than one circle. The largest photoconductor drum rotates 2-3 turns, and the feed roller can rotate more than 10 turns. When there are equally spaced marks on the paper, it may be caused by dirty or damaged rollers. Suppose a roller is stained. When it turns, it leaves a mark whenever the stain comes into contact with the paper. Source: Kunming Wushunda Economic and Trade Co., Ltd.
If the stamps are closer together. It may be formed by small rolls. If there is a long distance between them, larger rolls should be inspected.
The distance between the blots was measured and the diameter of the roll of the blot was calculated using the formula:
Roll diameter = print distance / 3.1416
For HP series printers, the drum diameter is approximately 91mm (3.75 inches) and the developer roller is 51mm (2 inches). The fuser roller is 76mm (3 inches). If the roller diameter is calculated to be 91mm (3.75 inches) based on the printing distance, the photosensitive drum should be checked first.
The photosensitive drum is worn or scratched and should be replaced. The remaining rollers should be dirty and clean. Replacement cleaning blade for aging of cleaning blade
Some reprints appear on the print