White Spots / Black Spots - Ricoh G108 Service Manual

IMAGE QUALITY

4.2.15 WHITE SPOTS / BLACK SPOTS

Symptom
A white spot ("firefly" image) appears in
dark areas or a black spot appears in white
areas.
Possible Cause
1) Foreign particles adhering to the
OPC belt or the transfer belt.
2) The OPC belt or the transfer belt unit
is damaged.
3) Unwanted particles are mixed in with
the toner.
4) Foreign particles adhering to the transfer roller, or partial deformation of the
transfer roller.
Countermeasures
1) Clean or replace the OPC belt unit.
2) Clean or replace the transfer roller unit. Replace the rear cover if necessary.
3) Replace the development unit.
4) Replace the transfer roller unit.
4.2.16 MIXED COLOR IMAGE
Symptom
A mixed color image appears in the print.
Possible Cause
1) Retraction error of the development
unit.
2) Retraction error of the transfer roller.
3) Retraction error of the transfer-belt
cleaning unit.
Countermeasures
1) Check where the mixed color image
is caused.
a) If it is on the OPC belt, the cause
is the retract error of the toner
cartridge.
b) If it is on the transfer belt, the
cause is the retract error of the
transfer belt or cleaning roller.
2) Replace the spring clutch or the development solenoid.
3) Replace the transfer roller clutch.
4) Replace the transfer-belt cleaning solenoid.
G108 4-16
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