Tektronix Phaser 780 Color, Service Quick Reference Manual

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Phaser 780 Color Printer
Light (undertone) prints
The overall image density is too light.
The printer displays no error code.
1.
Inspect the paper that is
loaded in the paper tray.
Check that the paper is not
wrinkled or moist. Also
ensure it is the correct weight.
Card stock must be feed from
the multi-purpose tray.
Recycled paper and paper
less than 24 lbs may produce
less than optimum quality.
2.
Clean and inspect the auto-
density calibration sensor. Test
the sensor using the printer’s
built-in diagnostics. If an error
11, 12, or 13 is detected, replace
the auto-density calibration
sensor.
3.
Print Service Test Print 1 on B-
size paper and open the front cover just as the sheet of paper starts to exit
the fuser. Inspect the image on the sheet of paper
before it reaches the fuser
rollers. Is the image density normal before it reached the fuser rollers? If no,
go to Step 4. If yes, go to Step 7.
4.
Remove the imaging unit.
5.
Inspect the test print image on the accumulator belt. Does the image
appear completely transferred to the accumulator belt? If yes, replace the
second bias transfer roller. If not, replace the accumulator belt.
6. Print Service Test Print 1 and inspect the image on the sheet of paper. Is
the image density now normal? If not, replace the high voltage power
supply.
7. Print Service Test Print 1 again and inspect the image on the sheet of paper
after it exits the fuser rolls. Is the image light when it exits the fuser? If
yes, replace the oil roll cartridge.
8.
Generate a test print.
9. Inspect the image on the sheet. Is the image density now normal as it exits
the fuser? If not, replace the fuser.
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