2G4
1-4-16
(3) Dropouts
(4) Black dots
(5) Black horizontal streaks
Copy example Causes Check procedures/corrective measures
Defective developing roller (in the
developer unit).
If the defects occur at regular intervals of 47.2 mm/1
7/8", the
problem may be the damaged developing roller (in the devel-
oper unit). Replace the developer unit (See page P.1-5-6).
Defective drum unit. Defective drum unit. If the defects occur at regular intervals
of 94 mm/3
11/16", the problem may be the damaged drum
(in the drum unit). Replace the drum unit (See page P.1-5-6).
Defective fuser unit. Defective fuser unit. If the defects occur at regular intervals
of 63 mm/2
1/2" (heat roller or press roller), the problem may
be the damaged fuser unit. Replace the press roller or heat
roller (See page P.1-5-10).
Defective paper specifications. Defective paper specifications. Paper with rugged surface or
dump tends to cause dropouts. Replace paper with the one
that satisfies the paper specifications.
Defective transfer roller installation. The transfer roller must be supported by the bushes at the
both ends. Clean the bush to remove oil and debris. Replace
the transfer roller if necessary (See page P.1-5-5).
Defective engine/high voltage PWB
(transfer bias potential).
Check the transfer bias output on the engine/high voltage
PWB. This requires removal of the left cover and the test
equipment. Replace the engine/high voltage PWB if high
voltage potential is not available on the PWB (See page P.1-
5-14).
Copy example Causes Check procedures/corrective measures
1. Defective drum unit. Defective drum unit. If the defects occur at regular intervals
of 94 mm/3
11/16", the problem may be the damaged drum
(in the drum unit). Replace drum unit (See page P.1-5-6).
If the defects occur at random intervals, the toner may be
leaking from the developer unit and drum unit. Replace
developer unit and drum unit (See page P.1-5-6).
Copy example Causes Check procedures/corrective measures
Defective drum unit’s ground. Defective drum unit’s ground. The drum axle in the drum unit
and its counter part, the grounding tab in the printer, must be
in a good contact. If necessary, apply a small amount of elec-
tro-conductive grease onto the tab.
Defective drum unit. Defective drum unit. Replace the drum unit (See page P.1-5-
6).
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