Service Guide
59
Small, repeating light dot in one color in-line with each other
This can usually be traced to a dent-like
defect in the developer roller of the
toner cartridge in question. Measure the
spacing between the spots. The distance
between the repeating spots indicates
the source of the problem.
In some instances, the spots may be dark
instead of white. They may also be
shaped something other than round.
■
The dents should be 3.4 cm (1.5 in)
apart or 2.5 cm (1 in.) for 1200 dpi
printing. No toner is transferred
from the developer roller to the
photoconductive belt at the defect
point.
■
If the spots are about 12.5 cm (5 in.)
apart, then the problem is a defect
on the fuser roller. Replace the
fuser.
■
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.
9922-76
Summary of Contents for Phaser 740
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Page 48: ...36 Phaser 740 and 750 Color Printers ...
Page 102: ...90 Phaser 740 and 750 Color Printers ...
Page 104: ...92 Phaser 740 and 750 Color Printers ...
Page 124: ...112 Phaser 740 and 750 Color Printers ...
Page 129: ...Service Guide 117 Figure 3 Motor and fan FRUs 3102 37 1 10 9 5 8 7 2 6 4 3 ...
Page 131: ...Service Guide 119 Figure 4 Sensor switch and flag FRUs 3102 40 1 7 2 3 4 8 5 6 ...
Page 135: ...Service Guide 123 Figure 6 Imaging and paper feed component FRUs 3102 39 1 2 3 7 9 4 6 8 5 ...