Samsung ML-1755 Service Manual page 59

T RO U B L E S H O OT I N G
7.1.3 Horizontal Black Band
1. Dark or blurry horizontal stripes occur in the printing periodically.
• Description
(They may not occur periodically.)
Digital Printer
1. Bad contacts of the voltage terminals to
Digital Printer
Digital Printer
Digital Printer
Digital Printer
2. The rollers of developer may be stained.
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.
Digital Printer
1. If dark or blurry black spots occur periodi-
Digital Printer
Digital Printer
Digital Printer
Digital Printer
2. If faded areas or voids occur in a black
3. If a black image is partially broken, the
Training Manual
7-2
Check and Cause
developer.
Charge roller = 37.7mm
Supply roller = 37mm
Develop roller = 35.3mm
Transfer roller = 45.3mm
Check and Cause
cally, the rollers in the Developer may be
contaminated with foreign matte or paper
particles.
( Charge roller : 37.7 mm interval
OPC drum : 75.5 mm interval)
image at intervals of 75.5 mm, or black
spots occur elsewhere, the OPC drum
surface is damaged.
transfer voltage is abnormal or the trans-
fer roller's life has expired.
Solution
1. Clean each voltage terminal of the Charge,
Supply, Develop and Transfer roller.
(remove the toner particles and paper par-
ticles)
2. Clean the right Gear that has relatively
small gap of the teeth in the OPC.
3. If the malfunction persists, replace the
developer.
Solution
1. Run OPC cleaning Mode Print and run the
Self-test 2 or 3 times.
2. In case of 75.5 mm interval unremovable in
1, cleanly remove foreign substances stuck
on the OPC location equivalent to black
spots and white spots with a dry duster.
3. The transfer roller guarantees 60.000
sheets printing. If the roller's life is expired,
replace it.
4. In case of 37.7 mm interval unremovable in
1, take measures as to replace the develop-
er cartridge and try to print out.
5. Clean the inside of the set against the paper
particles and foreign matter in order not to
cause the trouble.
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