White Spots on black text ; and graphics at 3.7 in. ; Black Spots at 3.7 in. (94 mm) - Page 125

Troubleshooting and routine maintenance

111

Hollow print

„

Make sure that you use paper that meets our specifications. (See 

Acceptable paper and other media

 on page 12.) 

„

Choose 

Thick paper

 mode in the printer driver or in the machine

’

s Paper 

Type menu setting, or use thinner paper than you are currently using. (See 

Paper Type

 on page 18 and 

Basic tab in the Software User

’

s Guide on the 

CD

-

ROM

.)

„

Check the machine

’

s environment. Conditions such as high humidity can 

cause hollow print. (See 

Choosing a location

 on page 88.)

„

Clean the primary corona wire on the drum unit. (See 

Cleaning the corona 

wire

 on page 130.) If the print quality has not improved, put in a new drum unit. 

(See 

Replacing the drum unit (DR-520)

 on page 135.)

All black

„

Clean the primary corona wire on the drum unit. (See 

Cleaning the corona 

wire

 on page 130.) If the print quality has not improved, put in a new drum unit. 

(See 

Replacing the drum unit (DR-520)

 on page 135.)

„

The drum unit may be damaged. Put in a new drum unit. (See 

Replacing the 

drum unit (DR-520)

 on page 135.)

White Spots on black text 

and graphics at 3.7 in. 

(94 mm) intervals

Black Spots at 3.7 in. (94 mm) 

intervals

Dust, paper powder, glue, and so on may stick to the surface of the photosensitive 
drum (OPC) and cause black or white spots to appear on printed documents.

Make a few copies of a blank, white sheet of paper. (See 

Making multiple 

copies

 on page 76.)

If you still see the spots on printed documents after making multiple copies, clean 
the drum unit (see 

Cleaning the drum unit

 on page 131).

If the print quality still has not improved you need to install a new drum. (See 

Replacing the drum unit (DR-520)

 on page 135.)

Black toner marks across the 

page

„

Make sure that you use paper that meets our specifications. (See 

Acceptable paper and other media

 on page 12.)

„

If you use label sheets for laser printers, the glue from the sheets may 
sometimes stick to the OPC drum surface. Clean the drum unit. (See 

Cleaning the drum unit

 on page 131.)

„

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 drum unit may be damaged. Put in a new drum unit. (See 

Replacing the 

drum unit (DR-520)

 on page 135.)

Examples of poor print 
quality

Recommendation

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