NEC Super Script 4400 Maintenance Manual page 231

9. Black Line - Fine black line appears in the printed image.
Main Causes
1. Wire grid of the charger unit is smeared.
2. photoconductor belt's surface is damaged.
3. Foreign particles (paper dust, etc.) are stuck in between the cleaning blade and photoconductor belt.
4. Debris adhering to the base of toner module's developer roller contacts to photoconductor belt.
OPC Belt Cartridge
Countermeasures
1. Remove the belt module.
a. Clean the charger unit. (See Chapter 7)
b. Replace the photoconductor belt module. (See Chapter 6)
2. Clean the surface of developer roller.
222 SuperScript 4400 — Maintenance Guide
Foreign
Particles
Cleaning Belt
OPC Belt Cartridge
Developer Roller
K
Y
M
C
Charge
Toner Module
K(Black)
Y(Yellow)
M(Magenta)
C(Cyan)