Tektronix Phaser 740, Service Manual

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Phaser 740 and 750 Color Printers
Dirty background
1.
Inspect the scorotron charger for toner or other contamination.
2.
If excess printing in background is of one primary color, replace that color’s
toner cartridge.
3.
Replace the high-voltage board.
4.
Dirty background can occur if the customer prints prolonged volumes of
monochrome (single primary color) prints. Replace the toner cartridge that is
overused.
5. Check color calibration adjust values.
Stains on the back of the print
1.
Replace transfer kit.
2. Empty the waste bin of the second bias transfer roller.
3. Clean the paper path of the paper feeder.
4. Inspect the fuser rollers for contamination. Replace the fuser.
5. Replace the paper feeder.
Some stains may appear on the back of Legal-size media. This is a limitation of the
print engine.
Ghosting
Ghosting with some images is unavoidable because of the color structure of the
images. If a color is used at one part of the image area and the same color is used
again at a later area, it is very possible to get ghosting of the first image into the second
image area after one revolution of the toner cartridge developer roller. This occurs
because the charge that is created from the first use of the color was not totally
extinguished. A small residual charge remains associated with the color, resulting in a
second use of the color to be darker in the same areas as the first image. This results in
the first image ghosting into the second image when the same color is used.
1.
A new toner cartridge exhibits less ghosting. Ghosting increase as toner
cartridges age.
Unfused or partially fused printing
1. Is the paper in good condition and appropriate for a laser printer?
2.
Is the printer printing within its environmental specifications?
3.
Run 10 to 20 blank sheets of paper through the printer.
4.
Replace the fuser unit.