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COMMON LASER TONER CARTRIDGE FAULTS AND PRINT DEFECTS
BACKGROUNDING.
Description: Shows as a fine grey coverage over the whole page.
Causes: Wrong toner, toner in poor condition, wrong OPC, worn doctor blade, Humidity
Drum Interval – Portrait
Description: Black or dark horizontal bars running from top to bottom of the page.
If three or four to a page, with a clean edge to the fault, it is likely to be from a light burnt drum. Light
exposure can occur with 18 minutes of a drum being exposed to light. This can be rectified by leaving
cartridge in a light proof box / bag for 2 days. The remove and re-test. Please note, the fault is highly
likely to return.
If six/eight to a page then it is likely to be a PCR with a serious fault.
This can also be caused by an intermittent fault in the electrical contact to the PCR.
BLACK LINE OR LINES RUNNING FROM TOP TO BOTTOM OF PAGE.
A scratched drum with a 360 degree scour running around its circumference shows as a thin line
running down the page. Multiple scours means more lines.
BLACK OR DARK BAND/S RUNNING FROM TOP TO BOTTOM OF THE PAGE.
A badly damaged wiper blade in one or more places.
A piece of paper from a paper jam or foreign material such as a build up of paper fluff caught between
the recovery blade and wiper blade.
BLACK RANDOM SPOTS APPEARING ON PAGE. (TONER SPLATTER)
This is usually caused by a damaged recovery blade allowing toner to get back onto the drum. Can also
be from a faulty wiper blade, though less likely.
BLACK REPETITIVE SMALL OR LARGE SPOTS APPEARING DOWN THE PAGE.
These can be caused by: Visible pinholes or chips on the drum’s outer surface or small non visible
pinholes in the drum’s substrate coating.
BLACK TO DARK REPETATIVE ROUNDED CONE SHAPES DOWN THE PAGE.
These are usually large and associated with PC copiers and the fault can appear on both sides of the
page. This is a worn drum. If small, the problem can be a damaged magnetic roller air gap bushes.
Found in both PC and laser cartridges.

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Tyre Tracks
Description;
Marks resembling tyre tracks running down the page.
Causes:
Worn doctor blade, worn magnetic roller sleeve or low humidity
BLACK PATTERNS LOOKING LIKE BUNCHES OF GRAPES OR CROCODILE SKIN. (Grapes of Wrath)
This can be caused by a faulty electrical connection to a corona wire or excessive toner appearing
on the drum due to a faulty electrical connection to the drum earth.
DARK GREY WAVY PATTERNS APPEARING ACROSS AND DOWN THE PAGE (SAND DUNING).
These patterns can be seen as narrow or broad repetitive bands anywhere across the page. This
indicates a faulty
magnetic roller sleeve.
COMPLETELY BLACK PAGE.
Faulty completely open circuit electrical connection to a PCR or Corona Wire.
PCR or Corona left out when remanufacturing.
This can also be caused by a high static charge trapped inside the cartridge.
COMPLETELY BLANK PAGE.
Faulty completely open circuit electrical connection to the magnetic roller.
DARK PRINTING.
A page that is printing dark over its whole area is possibly due to a high sensitivity drum. This can
be rectified by adjusting the printer’s intensity setting.
A page that exhibits some dark characters appearing at random or down a page in one or more
areas is indicative
of a faulty doctor blade causing a build up of excessive toner on one or more spots on the
magnetic roller.
GHOSTING; POSITIVE (A FAINT IMAGE OF ORIGINAL APPEARING FURTHER DOWN THE PAGE).
Cause: Poor fusing caused by a worn or defective fuser or wrong toner. In extreme cases, this
could be caused by a faulty wiper blade.
GHOSTING (NEGATIVE)

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Causes: Worn or defective PCR, worn or incorrect OPC, worn Magnetic roller sleeve or unmatched
MRS / toner / doctor blade.
LIGHT PRINTING.
Varying light to normal printing in a repetitive pattern down the page can be caused by: Faulty
PCR, faulty connection to a magnetic roller or a faulty magnetic roller sleeve.
Continuous light printing can be caused by a faulty magnetic roller sleeve. Poor quality toner or a
low sensitivity drum.
A low sensitivity drum can usually be compensated by adjusting the printer’s intensity setting.
Originally dark printing with the centre gradually printing light and spreading from the centre
towards the edge of the page after only about 6 to 10 pages indicate the cartridge is running out
of toner. A common problem is the user not removing the seal before using.
Light printing in bands from the top to the bottom is indicative of a faulty magnetic roller sleeve.
This is especially prevalent in the HP2100, 4000 and 5000 cartridges.
WHITE THIN LINE/S RUNNING FROM TOP TO BOTTOM OF PAGE THROUGH PRINTED
CHARACTERS.
This is normally caused by wear on the doctor blade or a worn magnetic roller sleeve.
VOIDS
Causes: Incorrect toner, damaged toner or wrong toner / opc combination