Print Quality Defect When Manual Duplexing

When duplexing a job on an HP Color LaserJet or LaserJet series printer, the leading edge of the second page appears smudged along the leading edge when multiple pages are duplexed. This is the result of toner from the first image being wiped onto the separation pad when picking the page to print the second image.

This arises if the first image has toner in the pick area (the area of the page that stops between the pick roller and separation pad). The pick process causes some of the toner from the first image to be deposited onto the separation pad. When the next page is picked, some of that toner from the separation pad gets deposited onto the first image creating the image defect.

 The first image does not have the defect since there is no toner on the separation pad when it is picked from the tray. The defect may or may not be seen on later pages when the second image is printed depending on the job. For example, multiple copies of a single page versus a job with unique images on each side of each page.

Figure 1: Manual duplex PQ defect

Perform the following steps to troubleshoot this issue:

Change the fuser temperature by changing the paper type. The greatest success has been with the heavy media type; however, other media types may resolve the issue.

Try changing the Optimize settings in the HP Toolbox or printer driver. Settings such as High Humidity may resolve the issue.

Try alternate paper from a fresh, unopened ream. Try a different type of paper that may have a more smooth texture.

Check the environment to determine if the unit is positioned under a window or near a vent. Try moving the printer to another room to determined if the issue is caused by environment.

Remove the unit from any power strips or UPS devices and plug directly into the wall.

If the printer has a 250-sheet tray (or other tray), print the first page from that tray then turn the page over and print from the manual feed tray. The pick roller from the 250-sheet tray (and other trays) has a lower pick force than the manual feed tray.

If possible, try lowering the image on the page. If the image has to have toner in the pick area, try to print those images second on the page.