Xerox 8500DN Service Manual - Page 65

Printer Self-Maintenance Theory of Operation The printer has several automatic or semi-automatic maintenance functions. These functions may be started automatically after a certain number of prints or during printer startup, or they may be started by the customer if a printquality defect is noted. ■ Printhead Maintenance Cycle (Eliminate Light Stripes) ■ Preheater Cleaning (Remove Print Smears) ■ Transfix Roller Oiling ■ Drum Cleaning (Chase Page) Printhead Maintenance Cycle (Eliminate Light Stripes) The Printhead maintenance cleaning cycle removes bubbles or foreign matter that cause a Printhead jet to malfunction. Three basic actions take place during a cleaning cycle: ■ Purging ■ Wiping ■ Printing the Cleaning Page There is one basic type of cleaning cycle performed by the purge system. The first customer purge and the manufacturing purge consist of two basic cleaning cycles performed sequentially. A cleaning cycle is performed when the printer is first powered on, if the ink reservoir has cooled to the point that a cleaning cycle is triggered. A cleaning cycle is not performed when the printer is coming out of standby mode. Refer to the purge system topic in this chapter for more detail on the Printhead maintenance cycle. Warning When servicing the printer be careful of the purge system as it passes the Printhead. If a damaged Wiper Blade catches on the Printhead, it could propel hot liquid ink upward into your face. Phaser 8400/8500/8550/8560 Color Printer Service Manual 2-33