Brother HL-4000CN - Page 290

V-80
<All blank>
Fig.5-23
Condition:
Print is wholly white.
Initial check:
Parts of different specifications, improper installation, damage, deformation, dirt, foreign
substance attached, etc.
Major parts to be checked:
Print head cartridge ASSY, Fuser ASSY, Transfer roll cartridge ASSY, Scanner ASSY,
MCU and HVPS PWB, Toner cartridge
Item Check Remedy
1
Toner empty
Check if the toner cartridge is full with toner.
Replace the toner
cartridge
2
Laser beam path interrupted
Check the laser beam path between scanner ASSY
and the drum in print head cartridge ASSY for
evidence of dirt or foreign substances.
Clean dirt or foreign
substances
3
Faulty scanner ASSY
Is the image quality improved if scanner ASSY is
replaced?
Replace the scanner
ASSY
4
Faulty charging or developing
Is the image quality improved if print head cartridge
ASSY is replaced?
Replace the print head
cartridge ASSY
5
Faulty transfer
Is the image quality improved if transfer roll
cartridge is replaced?
Replace the transfer roll
cartridge ASSY
6
Faulty MCU and HVPS PWB
Is the image quality improved if MCU and HVPS PW
is replaced?
Replace the MCU and
HVPS PWB