Xerox Phaser 8500, Service Manual

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Phaser 8400/8500/8550/8560 Color Printer Service Manual 2-33
Theory of Operation
Printer Self-Maintenance
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 print-
quality 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.