HP LaserJet 9040/9050 Service Manual - Page 260

Media troubleshooting Media defects can cause jams and image defects. If the previously described conditions are corrected and do not eliminate the printing problem, continue to investigate the media as the source of the defect. Problems with media are sometimes difficult to detect. Follow a standard troubleshooting procedure to help isolate media-related problems. The following are the steps to follow: z "Determine the problem source: media or printer" on page 244. z "Isolate a paper path" on page 244. z "Isolate a media brand" on page 245. z "Isolate a media type" on page 245. z "Operating environment" in chapter 2. z "Paper-path test" on page 213. Determine the problem source: media or printer When determining the cause of a printer failure, a distinction must be made between problems that relate to the printer itself and those that involve media. Often a problem that seems to be related to the printer is actually a matter of poor print-media selection or handling. To determine whether a problem is caused by the printer or by the media, try a few simple steps to remedy the situation: z Turn the media over in the tray to print on the reverse side. z Rotate the sheets 180° (end to end) to feed with a different leading edge. If the symptoms cease, or change in some way, assume that the problems are caused by the media. Isolate a paper path Try using the straightest paper path Some problems can be avoided by using the straightest available paper path. Usually this means media feeds from the upper paper tray or tray 1, and exits into the face-up bin. This path is recommended for envelopes and labels. Determine if the problem is caused by the duplexing process Media that has just made a pass through the printer can show increased media curl. Media curl increases image dropout, and creates pickup and stacking problems. When the second pass is made, media might not meet the specifications for moisture and curl. Dry media can hold static charges that affect print quality and stacking of the duplexed page. Media shrinkage resulting from a second pass through the printer can cause image misalignment on the duplexed page. Isolate the source of the jam Define the source of the media that jams. Determine where media jams occur Check where media stops when a jam occurs. 244 Chapter 7 Troubleshooting