Tektronix Phaser 780 Color, Service Quick Reference Manual

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56
Phaser 780 Color Printer
Repetitive mark appears on each print
An identical mark or image appears on each, or every other, printed image.
1. If spots repeat every 264 mm (10.4 in.) or appear to move in the direction
of paper travel from print to print, replace the imaging unit. If a defect
repeats in exactly the same place on successive prints, replace the
accumulator belt assembly.
2. If a problem repeats every 117 mm (4.5 in.), replace the fuser. If a problem
repeats every 107 mm (4.25 in.), replace the fuser roll cartridge.
3. An 88 mm (3.5 in.) smear may occur on the first print made after a new
imaging unit is installed due to the misalignment of the imaging unit’s gear
teeth with its drive gear. Once printing starts, the teeth will mesh properly
and the problem will disappear.
4. A defect every 58 mm (2.5 in.) or less is related to the feed or exit rollers.
Residual image or ghosting
There are faint, ghostly images
appearing on the page. The images
may be either from a previous page or
from the page currently being printed.
The printer displays no error code.
1.
Was the customer printing
numerous copies of the same
image? Avoid printing numerous
copies of the same image.
2. Generate a test print and open the
front cover just before the sheet of
paper enters the fuser.
3. Remove the imaging unit.
4. Inspect the image on the drum. Is
there a normal image, without
ghosts, visible on the drum? If no,
replace the erase lamp. (A failing
high-voltage power supply can
also cause ghosting.)
5.
If the customer is consistently printing 250 B-size (500 A-size) prints a day,
recommend the Hi-Duty Fuser Roll Cartridge. If fuser damage is
excessive, replace fuser and install Hi-duty Fuser Roll Cartridge.
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