NEC Super Script 4400 Maintenance Manual page 229

7 . White Line II - Vertical white line appears from the leading edge to the trailing edge of printed image.
Main Causes
1. Dustproof Glass of Optical Unit is smeared with toner or foreign particles.
Laser WARNING Label
Optical Unit
Countermeasures
1. Clean the dustproof glass.
a. Remove the belt module and toner module. (See Chapter 7)
b. Remove the dustproof glass from the optical unit.
c. Clean the dustproof glass. (See Chapter 7)
220 SuperScript 4400 — Maintenance Guide
OPC Belt Cartridge
K
Y
M
C
Dustproof Glass
OU Cover
Toner Cartridge
(K,Y,M,C)
Optical Unit
Paper Cassette
Knob
Dustproof Glass