Brother International HL-3400CN Service Manual - Page 306

CHAPTER

8

TROUBLESHOOTING

1-3

Jitter

Phenomenon

Uneven

optical

density

appears

periodically

in

the

horizontal

direction

on

the

printed

image

as

shown

in

print

sample

(3)

of

Page

8-45.

Main

Causes

(1)

Failure

of

main

motor.

i)

Irregular

rotation

of

the

drive

motor.

ii)

Failure

of

the

gears.

iii)

Variation

of

OPC

belt

running

speed

due

to

above

reasons.

(2)

Failure

of

the

OPC

belt.

Countermeasures

(1)

Replace

the

main

motor

with

a

new

one.

(2)

Replace

the

OPC

belt

cartridge

with

a

new

one.

NOTE:

If

the

print

mode

is

set

to

CAPT

(Color

Advanced

Photoscale

Technology)

in

the

driver,

this

problem

might

occur.

Change

the

mode

setting

to

normal

mode.

1-4

Ribbing

Phenomenon

Light

print

occurs

on

the

right

or

left

hand

side

of

the

image

as

shown

in

print

sample

(4)

of

Page

8-45.

Main

Causes

(1)

Slight

tilt

on

the

surface

of

printer

installation

table.

(Tilt

should

be

less

than

1°.)

(2)

Toner

amount

in

the

toner

cartridge

is

insufficient.

(3)

Toner

concentrates

to

one

side

in

the

toner

cartridge

since

the

toner

cartridge

is

not

level.

(4)

The

spring

at

the

back

of

the

developer

unit

is

deformed.

(5)

The

front

cover

unit

is

not

firmly

closed.

Fig.

8-2

Countermeasures

(1)

Confirm

that

the

printer

installation

table

is

flat

and

level.

(2)

Shake

the

toner

cartridge

horizontally

several

times

to

remedy

the

concentration.

(3)

Replace

the

toner

cartridge

with

a

new

one.

(4)

Confirm

the

open/close

position

of

the

front

cover

to

be

firmly

closed.

8-48

Brother International HL-3400CN Service Manual - Page 306

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