HP 2100 Service Manual - Page 139

Media Troubleshooting Media defects cause both paper jams and image defects. If correcting the previously described conditions does not eliminate the printing problem, investigate the media as the source of the defect. Problems with paper are sometimes difficult to detect. Following a standard troubleshooting procedure may help isolate media-related problems. The steps to follow are: • Determine if the problem is "A Paper or Printer Problem?" (page 129)? • "Isolate a Paper Path" (page 129) • "Isolate a Paper Brand" (page 130) • "Isolate a Paper Type" (page 132) • "Evaluate Paper User Practices" (page 137) • "Evaluate Environmental Conditions" (page 137) A Paper or Printer Problem? When determining the cause of a printer failure, a distinction must be made between problems relating to the printer itself and those involving paper. Often a problem which first appears to be related to the printer is actually a matter of poor paper selection of handling. To determine if a problem is caused by the printer or the paper, following a few simple steps can be helpful: • Turn paper over in the tray to print on the reverse side. • Rotate sheets 180 degrees (end to end) to feed with a different leading edge. If the symptoms cease, or change in some way, it can be assumed that the problems are caused by the paper. 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 paper will feed from the upper paper tray or manual feeder, and exit into the rear output tray (if available). This path is recommended for envelopes and media with a heavy basis weight. Determine if the problem is caused by duplexing Paper that has just made a pass through the printer can show an increase in paper curl. This paper curl increases image dropout, and pick-up and stacking problems. When the second pass is made, paper may no longer meet the specifications for moisture and curl. Dry paper may hold static charges which affect print quality and stacking. Image misalignment front-toback on a duplexed page may be caused by paper shrinkage. C4170-90959 Media Troubleshooting 129