Xerox Phaser 7700 Fixed quality

From the front panel’s Printable Pages
Menu, select Service Pages, then select Print Repeating Defects Pages.
2. Swap the Print Cartridges. If the defect still appears in the same color, the
problem is the developer. If the banding traveled, it is the print cartridge. All
colors is a problem with the Accumulator Belt.
3. Replace the Accumulator Belt Assembly (RRP 35, on page 7-180).
4. If the banding frequency is high (.5 mm), replace the Laser Unit