Xerox 7700DX Service Manual - Page 151

Light Bands, Dark Bands, or Mottled Prints, Cause, Procedure

Page 151 highlights

Light Bands, Dark Bands, or Mottled Prints An image void, dark bank or mottle in a primary CMYK color, or a visible area on the Developer Roller where toner is missing. Cause Narrow image voids or a dark band in the process direction can be caused by contamination in the Developer Assembly. These contaminants have been attributed to vendor manufacturing processes or seal damage during disassembly and reassembly of the Developer. This contamination prevents Developer beads from flowing on to the Magnetic Roller correctly. s7700-566 Mottled prints can be a result of bead carryout. Bead carryout is when most of the beads in the Developer are carried out of the Developer Assembly into the Waste Toner Cartridge. s7700-567 Procedure 1. Replace the Developer beads of the effected color(s). In almost all cases, replacing only the Developer beads (RRP 28, on page 7-186) will resolve the problems. It is not usually necessary to replace the Developer Assembly (P/N 116-1115-00). 2. Thoroughly clean the Developer Assembly before installing the new Developer bead mix. Rotate the Developer Drive backwards during cleaing to ensure no contamination remains under the Magnetic Roller. When reinstalling the cover in step #4 of (RRP 28, on page 7-186), be careful not to tear or dislodge any portion of the Foam Seal. Phaser 7700 Color Laser Printer Service Manual 3-121

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Phaser 7700 Color Laser Printer Service Manual
3-121
Light Bands, Dark Bands, or Mottled Prints
An image void, dark bank or mottle in a primary CMYK color, or a visible area
on the Developer Roller where toner is missing.
Cause
Narrow image voids or a dark band in the process direction can be caused by
contamination in the Developer Assembly. These contaminants have been
attributed to vendor manufacturing processes or seal damage during
disassembly and reassembly of the Developer. This contamination prevents
Developer beads from flowing on to the Magnetic Roller correctly.
Mottled prints can be a result of bead carryout. Bead carryout is when most of
the beads in the Developer are carried out of the Developer Assembly into the
Waste Toner Cartridge.
Procedure
1.
Replace the Developer beads of the effected color(s). In almost all cases,
replacing only the Developer beads (RRP 28, on page 7-186) will resolve
the problems. It is not usually necessary to replace the Developer
Assembly (P/N 116-1115-00).
2.
Thoroughly clean the Developer Assembly before installing the new
Developer bead mix. Rotate the Developer Drive backwards during cleaing
to ensure no contamination remains under the Magnetic Roller. When
reinstalling the cover in step #4 of (RRP 28, on page 7-186), be careful not
to tear or dislodge any portion of the Foam Seal.
s7700-566
s7700-567