Lexmark T420 Service Manual page 90

4048–00x
White or Black Lines or Bands
FRU
Toner Cartridge
Paper Feed Drive Gears
Toner on Back of Page
FRU
Print Cartridge
Fuser Assembly
Transfer Roller
2-54
Service Manual
Action
Banding appears as light or dark
horizontal lines on a uniformly gray
page or on a page with a large area
of graphics. Banding is primarily due
to a variation in the speed of the
paper as it feeds through the printer
especially in the developer and
transfer process. Inspect the toner
cartridge and paper feed
components, especially the drive
gears, for signs of wear, debris,
binds, or damage.
Action
Inspect the overall paper path for
signs of spilled toner.
Gently clean the contaminated areas
with a soft cloth or compressed air.
The fuser hot roll can cause toner on
the back of the paper, if toner is
building up on the hot roll. This
buildup may transfer to the backup
roller, later transferring to the back of
the paper.
Inspect the hot roll and backup roller
for signs of contamination and
replace fuser assembly as
necessary.
A transfer roller contaminated with
toner can cause toner to transfer to
the back of printed pages.
Inspect the transfer roller for
contamination and replace as
necessary.