Xerox 770 User Manual page 138

Problem solving
Patterned, Mottled or Grainy Background
The background of your output is moire, has a rippled or digital pattern, prints with
squares or small blocks.
Remedy: Access the Sharpness/Color Saturation screen by selecting the Image Quality
tab.
Open, then fully close the Document Handler.
Place original face down and to the rear left of the document glass. Place a sheet of
blank paper on top of the original.
Black Lines, Streaks,Spots, Smears or Bands
Remedy: Before performing any of the following steps, ALWAYS check the status of
the CRUs/Supplies by pressing the Machine Status button and selecting the Supplies
tab.
Output contains black or gray stripes either dotted or continuous, has stratches or
undefined edges.
Remedy: For copy/scan jobs, perform the following:
• Access the Lighten/Darkencontrol by selecting the Image Quality tab.
• Access the Sharpness/Color Saturation screen by selecting the Image Quality tab.
• Check that the Sharpness scroll is set to a softer setting.
• If you are copying your original from the Document Glass, access the Original Size
screen by selecting the Original Size button on the Layout Adjustment tab.
• Clean the Document Glass.
• Ensure that the paper tray guides are against the edges of the loaded paper.
Color Lines, Streaks, Spots, Smears, or Bands
Remedy: For both network print jobs and copy/scan jobs, perform the following:
• If lines or streaks are present, check the IBT Cleaner Assembly for wear or damage,
and replace as required.
• If the defect occurs every 36 mm on the prints, do not replace the Drum. This interval
is caused by a damaged or defective Developer Housing.
• If lines, streaks, or deletions in the process direction appearonly with Black, then
replace the Black Scorotron Assembly.
• If spots or bands occur every 126 mm on the prints, theYellow, Magenta, or Cyan
Drum is damaged or light-shocked.
10-30 ®
Xerox 770 Digital Color Press
User Guide