HP LaserJet II Serie Manual De Instrucciones página 225

HP 33440/HP 33449 COMBINED SERVICE MANUAL
I
Corona Grid.
I
Grid is to ensure that the Primau
1. Dirty
Beam-to-Drum
Mirror.
2.
Dirty "Transfer
Corona.
3.
EP-S Cartridge.
4.
Laser/Scanning
Assembly.
Corona deposits a uniform negative
charge to the surface of the drum. If
the grid is not functioning properly,
uneven charges are deposited on the
drum's surface. The random areas of
uneven charges appear as dark blotches
in the print.
Table 7-26. Vertical White Streaks
The Beam-to-Drum Mirror reflects
the laser light from the smnner to the
surface of the photoconductive drum.
If the mirror is dirty, the laser light is
blocked and the image is not written
properly on the drum.
The purpose of the Transfer Corona is
to apply a positive charge to the back
of the paper to attract the negatively
charged toner image from the drum to
the paper. If potions of the Transfer
Corona are earemely contaminated or
blocked, vertid streaks would occur in
the printed output.
No toner is available for print,
The focusing lenses within the
Laser/Scanning Assembly may be
contaminated, blocking (or diffusing)
the laser light.
AC~ON
Replace the EP-S Cartridge.
[f the problem persists, refer
to Table 7-45, "High-Voltage
System Checks."
Carefully clean the Beam-to-
Drum Mirror. A quality camera
lens cleaning fluid and tissue
mn be used if necessary. The
mirror may be easily accessed
by moving the mirror shutter to
the right and folding it up out
of the way.
Clean the Transfer Corona
housing and wire per
instructions in Chapter 4,
Section 4-4.
Replace the EP-S Cartridge.
Replace the Laser/Scanning
Assembly.
7-61