Xerox WorkCentre C2424DX Service Manual page 279

Test Print Examples (Continued)
6: Gray Fill, Dot Size Uniformity
This print is made up of a 66% black fill. It
reveals variations in the ink-drop-spread
caused by thermal variations, transfix roller
pressure variations, or drum oiling variations.
Look for:
There is a large area of differences in the
1.
density across the width of the page (a
slight variation is normal). Look for a
lighter vertical band, about 1/3 the width
of the page, running the length of the
page. Look for small, light spots, or
irregular white lines, vertically aligned
with each other, in the print every
125 mm (5.0 in.).
Look for ink on the top and bottom
2.
margin of the page, or ink on the back of
the page. This pattern is sensitive to the
density variations in the paper it is printed
on. Use a high-quality grade of system
paper; otherwise, the print appears
mottled.
Causes:
Use the diagnostics to check the printhead and drum for correct thermal regulation.
1.
Ensure the drum fan is running properly. A vertical band, 1/3 of a page wide, running the
length of the page, is caused by a stuck heating plate in the paper preheater. Run the
control panel cleaning procedure
the paper preheater and may free the stuck heating plate. Additionally, you may manually
force a thick sheet of paper (65 to 80 lbs.) through the paper preheater to jar the plate
free. Light spots that repeat every 11.63 cm (4.58 in.) down the length of the page are
caused by a defective transfix roller. The roller has a soft spot that is not pushing the ink
into the paper as well as the rest of the roller. If you observe variations in the glossiness
of the print, replace the maintenance kit.
If there is ink on the top and bottom margin of the page or ink on the back of the page, it
2.
may be caused by the roller remaining down during the print. You may hear an unusual
noise if the Transfix Roller stays down and rubs against the drum. Inspect the Drive Train
and ensure that it self-homes between prints. The drive train is in its home position when
the two 1.5 mm holes found on the clear plastic cover align axially with corresponding
holes in the gear. Another way to verify that the drive train is in its home position is to
verify that the two small leaf springs from the clear plastic cover are seated correctly in
their corresponding gear detent slots. Inspect the perimeter of the cam lobes for surface
defects and check to see that the angular orientations of the cams match. Inspect the
transfix load arm return springs. Verify that the maintenance kit returns home between
prints. Inspect the cam shaft surfaces for damage. If all of these items are working
correctly, replace the process drive module.
7: Manuf. Five Duplex GSF
This print is used by manufacturing and
engineering only.
Image-Quality Troubleshooting
Clean Print Smears,
Light band Light band
Uneven fill Uneven fill Uneven fill
Should see Should see Should see
even fill even fill even fill
left to right left to right left to right
which raises the temperature of
s2424-096
5-39