Lexmark 5021-0XX - Manual (Page 201)

Diagnostic information 2-123
5021-0XX
White line II service check
Vertical white line appears from leading edge to trailing edge of
printed image.
Problem area Action
1 Laser unit assembly
(printhead) Dust proof glass of laser unit is
smeared with toner or foreign
particles. Clean glass:
• Remove toner cartridges and
photodeveloper cartridge. See
“Photodeveloper cartridge
removal” on page 4-11
.
• Open dust-proof glass cover.
• Clean glass.
There are foreign particles adhering
to laser beam opening of printhead.
Clean laser beam opening.
2 Toner cartridge Foreign particles mixed in toner
cartridge. Replace faulty cartridge.