Xerox Phaser 8860 Service Manual page 312

Figure 20 Purge System
Printhead Maintenenace
To perform a Printhead maintenance cycle, the Printhead is first tilted away from the Drum to
allow the Wiper Blade to pass by. The Wiper Blade is then raised in front of the Printhead. The
media path drive governs wiper movement when it engages the Head Maintenance Clutch on
the exit shaft of the system. The Purge Pump applies pressure to the ink reservoir for approxi-
mately 2.5 seconds. Valves in the reservoir seal when pressure is applied. The pressurization
ejects a small amount of ink from the jets. Following the pressure purge, the Printhead tilts into
the Wiper Blade and the wipe cycle begins. The pump runs again with the solenoid for approx-
imately 30 seconds, creating a neutral balance between pressure and ink. The Wiper Blade
lowers and wipes excess ink from the jets into the Waste Tray. A proper purge covers the length
of the Waste Tray with a single layer of ink about 20 mm wide.
The level of the ink in the reservoir is kept constant. If the purge tubing is pinched, the Print-
head may not purge properly. In addition, because the purge tubing also acts as a vent to
atmosphere when not purging, a more serious failure can occur if the ink overfills and the res-
ervoir cannot vent properly.
Theory of Operation
Image Output Terminal
When servicing the system be careful of the purge system as it passes the Printhead. If
a damaged wiper blade of the purge system catches on the Printhead, it could propel
hot liquid ink upward into your face.
Figure 21 Printhead Wiper Blade
09/2007
8-20
WARNING
Phaser 8860/8860MFP Service Manual
Initial Issue