Konica Minolta bizhub 20 User Manual page 131

Examples of poor print
quality
ABCDEFGH
abcdefghijk
A B C D
a b c d e
0 1 2 3 4
Black toner marks across the
page
ABCDEFGH
abcdefghijk
A B C D
a b c d e
0 1 2 3 4
Line across the page
ABCDEFGH
abcdefghijk
A B C D
a b c d e
0 1 2 3 4
Black lines down the page
Printed pages have toner
stains down the page
122
Recommendation
 Make sure that you use paper that meets our specifications. (See
Acceptable paper and other print media on page 12.)
 If you use label sheets for laser machines, the glue from the sheets
may sometimes stick to the OPC drum surface. Clean the drum unit.
Do not use paper that has clips or staples because they will scratch

the surface of the drum.
 If the unpacked drum unit is in direct sunlight or room light, the unit
may be damaged.
 The toner cartridge may be damaged. Put in a new toner cartridge.
(See Replacing a toner cartridge on page 143.)
 The drum unit may be damaged. Put in a new drum unit. (See
Replacing the drum unit on page 145.)
 Clean the laser scanner window and the corona wire inside the drum
unit. (See Cleaning the laser scanner window on page 138 and
Cleaning the corona wire on page 140.)
 The drum unit may be damaged. Put in a new drum unit. (See
Replacing the drum unit on page 145.)
Clean the corona wire inside the drum unit by sliding the blue tab. Be

sure to return the blue tab to the home position (
corona wire on page 140.)
 The toner cartridge may be damaged. Put in a new toner cartridge.
(See Replacing a toner cartridge on page 143.)
 The drum unit may be damaged. Put in a new drum unit. (See
Replacing the drum unit on page 145.)
 The fuser unit may be smudged. Call your KONICA MINOLTA dealer
for service.
). (See Cleaning the
a