290 Troubleshooting
Black or white bands appear in the printout
White dots appear in the printout
Print quality is uneven on the page
Cause What to do
There may be a problem with 
the photoconductor unit.
Replace the photoconductor unit. See 
“Photoconductor Unit” on page 246.
Check if the filter under the 
photoconductor unit is dirty. If it is dirty 
clean the filter. See “Cleaning the print 
head filter” on page 261
Cause What to do
Duplex printing on damp 
coated or thick paper may 
produce printouts with white 
dots where the toner density is 
high on the back of the paper.
Do not select Thick (Back) or Coated 
(Back) as the Paper Type setting in the 
printer driver. Choose Thick or Coated 
instead.
Do not store coated paper in a humid or 
damp environment. Be sure to use 
paper that is newly unwrapped.
Cause What to do
Your paper may be moist or 
damp.
Do not store paper in a humid or damp 
environment.
There may be a problem with 
the photoconductor unit.
Replace the photoconductor unit. See 
“Photoconductor Unit” on page 246.