Brother HL-3040CN, Service Manual, Page: 138 / 437

3-74
Confidential
■ One color spots or dirt
<
User Check
>
- Damp (wet) paper might be used. Try to changing to freshly unopened paper.
- Toner may be empty. Replace the toner cartridge with a new one.
- If the same problem occurs after printing a few pages, the adhesive of a label or the like,
paper powder or dirt may be attached on the surface of the exposure drum. Feed the paper
from the manual feed slot one to three times to clean the drum. (Refer to
“Drum cleaning
function of product” in this chapter .)
When the same problem occurs after feeding the drum cleaning sheet, wipe off the dirt on
the exposure drum with a cotton swab. (Refer to
“Drum unit cleaning” in the previous pages .)
- The drum unit may be damaged. Replace the drum unit with a new one.
- The belt unit may be damaged. Replace the belt unit with a new one.
Step Cause Check
Result
Remedy
1 Fuser unit failure Are the spots at 78 mm
(heat roller
circumference)
intervals? Yes Replace the fuser unit.
2 Toner/new
sensor PCB failure Is the “Replace Toner”
message indicated on
the LCD when replacing
the toner cartridge with
the one which has
reached the end of life? Yes Replace the toner/new
sensor PCB ASSY.