5-2 Phaser 7750 Printer Service ManualPrint-Quality Problems OverviewPrint-quality defects can be attributed to printer components, consumables, media,internal software, external software applications and environmental conditions. Tosuccessfully troubleshoot print-quality problems, as many variables as possible mustbe eliminated. The first step is to generate prints using printable pages embedded inthe printer on laser paper from the approved media list. The paper should be from anunopened ream that has been acclimated to room temperature and you should ensurethat genuine Xerox toner is installed in the printer.Print the “Paper Tips Page” for media that has been tested and approved for use in thePhaser 7750 Printer. If the print-quality defect is still present when printing onapproved media from an unopened ream of paper, then software applications, andenvironmental conditions need to be researched.Print a “Usage Profile” to determine the temperature and humidity the printer hasbeen operating under. Compare this to the environmental specifications for the printerfound in "Environmental Specifications" on page 1-13 of this manual. Temperatureand humidity extremes can adversely effect the Xerographic and fusingcharacteristics of the printer.When analyzing a print-quality defect, first determine if the defect occurs in all colorsor only one color and if it is repeating or random. Continuous defects in the processdirection, such as voids and lines, are the most difficult to diagnose. The visiblesurfaces of all rollers should be inspected for obvious defects.Defects Associated with Specific Printer ComponentsSome print-quality problems can be associated with specific assemblies, the mostcommon problems and the associated assemblies are listed below. Also, refer to thespecific print-quality troubleshooting procedure for more information.The ROSPotential Defects:■ Streaks from contamination on ROS windows (usually single color)■ Light Image (single color, or all colors)■ Banding (Slow Scan direction)
