Horizontal Black Band - Samsung ML-2251N/XAA Service Manual

Troubleshooting

7.1.3 Horizontal Black Band

1. Dark or blurry horizontal stripes occur in the printing periodically.
• Description
(They may not occur periodically.)
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7.1.4 Black/White Spot
1. Dark or blurry black spots occur periodically in the printing.
• Description
2. White spots occur periodically in the printing.
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Service Manual
7-2
Check and Cause
1. Bad contacts on the toner cartridge high
voltage terminals.
2. The rollers in the toner cartridge may be
contaminated.
Charge roller = 37.7mm
Supply roller = 44.9mm
Develop roller = 35.3mm
Transfer roller = 47.1mm
Check and Cause
1. If dark or blurry black spots occur periodi-
cally, the rollers in the Developer may be
contaminated with foreign matter or
paper particles.
( Charge roller : 37.7 mm interval
OPC drum : 75.5 mm interval)
2. If faded areas or voids occur in a black
image at intervals of 75.5 mm, or black
spots occur elsewhere, the OPC drum
surface is damaged.
3. If a black image is partially broken, the
transfer voltage is abnormal or the
transfer roller's life has expired.
Solution
1. Clean all HV terminals on the cartridge and
on the set frame. Ensure all toner or paper
dust particles are removed.
2. Clean the right Gear that has relatively
small tooth gap on the OPC.
3. If the problem persists replace the toner
cartridge.
Solution
1. Print several OPC cleaning Mode Prints
and then run the Self-test 2 or 3 times.
2. 75.5 mm repetition: Examine the surface of
the OPC drum and carefully clean with a
soft, lint free cloth. If unsuccessful replace
the cartridge.
37.7mm repetition: Replace the toner car-
tridge
3. The transfer roller guarantees 60,000
sheets printing. If the roller's life is expired,
replace it.
Note. Cleaning the inside of the set to
remove excess toner particles or paper
dust will reduce the occurrence of this
problem..
Samsung Electronics