clean compressed air.
3. Laser Glass: In the top lid of the printer, behind the hinged protective cover is the protective laser glass. This glass
should be periodically cleaned with a clean soft lint free cloth. If this glass becomes dirty, all of the pages printed will be
light in the areas of the dirt.
4. All of these items just covered, as well as the condition of the toner cartridge effect the print quality and should be
checked before taking test prints.
Since the most important part of the toner cartridge is the OPC drum, special attention should be taken with this part.
To help determine the condition of the OPC Drum, the printer’s intensity should be set to the darkest setting while
taking a test print. Having the intensity set to the darkest setting will help to show up any OPC Drum flaws that may not
show up with the intensity set to the normal mid setting.
5. To set the intensity, Turn the printer OFF-LINE. Press the LEVEL 2 button. Press the down arrow button until
DENSITY= appears on the display. Press the right arrow button, the word SET will appear. Press the Up arrow until 5
stars appear on the display. Press the right arrow button, the word SET will disappear. Press the ONLINE button 2X to
return to the READY state.
6. To run a test print, turn the printer OFF-LINE. Press the LEVEL 2 button. Press the down arrow until FEATURE PRINT
appears on the display. Press the right arrow button, the word PRINT will appear. Press the right arrow again, the
entire display will flash, and 1 page will print out. press the ONLINE button 2X to return to the READY state.
7. Once you have the print out’s, they need to be examined to determine possible cartridge defects. In general, any
marks on the paper that shouldn’t be there indicate a problem. You should also examine print areas for problems such
as light print, and poor black fills.
8. Some of the more common toner cartridge problems are:
Dirty Primary Charge Felt; Located inside the toner cartridge, this will show on the test page as small random small
dots usually on the top 1/3 of the page. All cartridges (OEM or rebuilt) have a tendency to do this to some extent, but if
the felt is dirty it will be very noticeable. Worn out primary change felt will appear on the test pages as light vertical gray
streaks - there is no fix for this, the cartridge should be disposed of.
9. Scratched drum; this is shown by a very thin, perfectly straight line that runs from the top to the bottom of the test page.
10. Chipped drum; This will show as a dot or series of dots that repeat 3 times per page. Any drum defects will repeat 3
times per page based on the drum circumference of 3.68"
11. Light damaged drum; This will show up as a shaded area on the test print that should be white. Again this will repeat 3
times per page.
12. Bad wiper blade; This will show as either a gray line approximately 1/8" thick, or as shading across the entire page. In
either case there will be a film of toner on the drum surface.
CARTRIDGE PRINTING THEORY
1. The toner cartridge printing process is best explained as a series of steps or stages. (See the following diagram).
2. The first stage in the printing process is the conditioning stage. This is where the Conductive Felt Strip places a uniform
negative DC voltage on the OPC drum surface. The amount of the negative DC voltage placed on the drum is
controlled by the printers intensity setting.
3. In the second stage (also called the imaging section), the laser beam is fired onto the OPC drum surface. The laser
beam dissipates the OPC drum charge to ground wherever it strikes the drum, leaving a latent electrostatic image. The
OPC drums circumference is 3.68" and therefore makes approximately three revolutions for each printed page.
4. The third or developing stage is where the toner is developed on the drum by the developing section (or supply
chamber), which contains the toner particles. Lets take a closer look at this section. The Static Roller in this cartridge is
different from most in that it is a foil type sleeve fit around a foam core. The toner is held to the static roller by a DC
voltage supplied by the high voltage power supply. This voltage is controlled by the printers intensity setting, and
causes either more or less toner to be attracted by the static roller. This in turn will either increase or decrease the
print density. The toner is first fed to the static roller by the feed roller. The amount of toner on the static roller is
controlled by the metal doctor blade which is gapped to keep the amount of toner on the static roller constant.
5. As the laser exposed areas of the OPC Drum approach the static roller, the toner particles are attracted to the drum’s
surface due to the opposite voltage potentials of the toner, and laser exposed areas of the OPC drum.
6. This image is then transferred to the paper as it passes below the drum by the transfer charge roller, which places a
positive charge on the back of the paper. This positive charge causes the negatively charged toner on the drum’s
surface to be attracted to the page. The small diameter of the drum, combined with the stiffness of the paper causes the
paper to peel away from the drum. The static charge eliminator weakens the attractive forces between the negatively
charged drum surface, and the positively charged paper. Without this help, thin paper may wrap itself around the drum.
7. The image is then fused on to the paper by the fuser assembly, which is comprised of the upper and lower fuser rollers.
The lower rubber roller presses the page up into the upper roller which then melts the toner into the paper. The upper
roller is a hard Teflon coated, heated roller.
8. The fourth stage is where the OPC drum is cleaned. On average, approximately 90% of the toner is transferred to the
paper during the print cycle. The remaining 10% remains on the OPC drum and is cleaned off the Drum by the wiper
