Canon LBP7660Cdn Manual page 937

When the settings are changed, sometimes residual images appear on non-printed areas.
Perform the following procedure.
1. Press [
Solution 3
2. Select [Special Print Mode] in [User Maintenance].
3. Set [Rough Paper Adj.] to [On].
<Cause 4> Toner does not fix to the paper in places with high density.
Set [Special Image Mode] to [Level 1].
If the problem still persists, set it to [Level 2].
"[Setup] Menu ([User Maintenance] Options)"
Solution
Normally, set [Special Image Mode] to [Off]. Do not set [Level 1] or [Level 2] unless the problems
described above occur.
If it is set to [Level 1] or [Level 2], the print density may be lower than if it was set to [Off].
<Cause 5> A problem is occurring inside the printer.
If <Ennn-nnnn> appears in the display, follow the procedure in
Solution
problem.
[Heavy 1] [Heavy 2]
[Heavy 2] [Heavy 3]
[Envelope] [Envelope H]
[Coated 1] [Coated 2]
[Coated 2] [Coated 3]
[Coated 3] [Coated 4]
] ( : Online).
"The Message Indicator Is On" to solve the