Phenomena
Cause
positions
Cause 1
Cause 2
Remedy
Edge
phenomenon
Developing
unit
Too much distance between developing roller and
OPC unit
Undertoner (insufficient toner supply)
Insufficient development (Insufficient toner on the
developing roller)
Toner charging failure (insufficient stirring of
developer and toner)
OPC drum unit installation incomplete
Developing unit positioning collar defect (deformation,
attachment of foreign material)
Developing unit installation incomplete
Doctor gap improper
Developing roller main electrode position improper
Developer defect
Toner concentration sensor defect
Developing shutter spring defect
Developing shutter defect
Developing roller rotation improper
Developing unit replacement
Drive
section
Toner supply failure
Shutter ring defect
Toner clutch defect (color)
Toner motor defect (black)
Developing shutter clutch solenoid position improper
Developing shutter clutch defect
Developing shutter drive gear defect
Developing roller clutch defect
Toner clutch replacement
Developing shutter clutch solenoid position adjustment
Developing shutter clutch replacement
Developing shutter drive gear replacement
Developing roller clutch replacement
OPC
drum
unit
Too much distance between developing roller and
OPC unit
Main charger charging insufficient
OPC drum charging insufficient
OPC drum unit mechanism section defect
Main charger defect (dirt)
Too much nip between transfer drum and OPC drum
OPC drum defect
Main charger cleaning
OPC drum unit replacement
High voltage
PWB
Main charger output failure
Developing bias output failure
Transfer bias voltage failure
High voltage PWB defect
High
voltage
PWB
replacement
Transfer drum
section
Uneven
transfer
Transfer drum defect (dirt, deformation)
Dew
Transfer voltage improper
Transfer drum replacement
Sensor
Temperature/humidity sensor malfunction
Toner concentration sensor malfunction
Image density sensor malfunction
Temperature/humidity sensor defect
Toner concentration sensor (developing unit) defect
Image density sensor defect
Temperature/humidity sensor replacement
Developing unit replacement
Image density sensor replacement
Image density sensor cleaning
PCU PWB
Print quality control data (NV-RAM) defect
Sensor malfunction
Load control defect
NV-RAM data disturbance, defect, peripheral circuit
defect
Temperature/humidity sensor input circuit defect
Toner concentration sensor input circuit defect
Developing shutter clutch control circuit defect
Developing roller clutch control circuit defect
Toner clutch (color) control circuit defect
Toner motor (black) control circuit defect
Developing motor control circuit defect
Main charger control circuit defect
Transfer bias control circuit defect
Developing bias control circuit defect
Discharger control circuit defect
Discharge lamp control circuit defect
Print quality control data (NV-RAM) correction by diag
PCU PWB repair, replacement
11 – 32
SHARP SERVICE MANUAL JX8200SM [11] TROUBLESHOOTING