Repeated Spots Or Lines On Print In-Line With Each Other; Dark Vertical Line In Print; White Horizontal Line Or Band In All The Colors Of A Print - Tektronix Z740/N - Phaser 740 Color Laser Printer Service Manual

Repeated spots or lines on print in-line with each other

1. Measure the spacing between the spots. The distance between the repeating
spots indicates the source of the problem.
Thin horizontal lines, depending on problem, the distance between lines may
range from 1.5 mm (1/20th inch) between each line to 103 mm (4 in.) between
each line. The gear are "chattering" in paper feeder. Apply a single drop of
molybdenum grease (brown grease) to each gear and let print action work the
grease into the gears. Avoid excess grease.
26.5 mm (1 in.): Toner cartridge at 1200 dpi. Replace the toner cartridge.
35 mm (1.3 in.): Toner cartridge at 600 dpi. Replace the toner cartridge.
76 mm (3 in.): Second bias transfer roller. Replace the transfer roller.
43 mm (1.7 in.): Imaging unit drive gear train.
95 mm (4 in.): Imaging unit belt roller defect. Replace the imaging unit.
102 mm (4.1 in): Paper feeder drive gear broken tooth. Replace the paper
feeder drive gear.
121 mm (5 in): Fuser roller defect. Replace the fuser.

Dark vertical line in print

1. Inspect the scorotron charger for toner or other contamination. If
contaminated, its charge wire will appear fuzzy.
2.
Replace the toner cartridge if the dark stripe is of one primary color.
3. Inspect the photoconductive belt for damage. Replace the imaging unit if
necessary.
4. Replace the fuser.

White horizontal line or band in all the colors of a print

1. Replace the imaging unit.
2.
Replace the second bias transfer roller. Inspect it for loose roller contacts.
Grease the end of the roller shaft with conductive grease.
Service Guide
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