Dirty Background - Ricoh FT4430 Service Manual

DIRTY BACKGROUND

Dirty Background on Entire Copy Image
1.
- Possible Causes -
Dirty corona wire
Toner supply clutch malfunction
Incorrect lamp regulator output
Dirty drum and bias thermistors
Inefficient drum cleaning
Incorrect corona current
Drum worn out
- Action -
Note: When the problem occurs after the drum conditioning, make several
white copies or cycle the development unit for 2 minutes using free run.
Make a reduced copy with A3/11" x 17" paper. Does the dirty background ap-
pear in the erased areas?
Y N
I
Clean the drum thermistor and bias thermistor surfaces.
F
I
If the problem was not resolved, adjust the lamp regulator output.
I
If the problem still exists, check and adjust the charge corona current.
; Clean the erase unit.
Clean the drum heater thermistor and bias thermistor surfaces.
F
Do wavy lines occur with the dirty background?
Y N
I
Does the toner supply clutch turn off?
N
Y
I
Is the toner supply solenoid (CN230-3) continuously supplied
with +24 volts.
Y
lean or replace the toner supply clutch.
1
N
I
Check/replace the dc power supply and/or the main board.
16 April '88