Ricoh D255-17 - Page 459

Service Call 490-491
SM 6-21 D255/D256/M281/M282
Troubleshooting
SC No. Type Error Name/Error Condition/Major Cause/Solution
SC491-01 D Drum Unit Type Mismatch Error
 Cannot communicate with the EEPROM of the drum PCB
normally.
 An incompatible drum unit is installed.
 Connector defective or disconnected
 Drum PCB defective
 Connect-Left PCB defective
 IOB defective
 Connector defective or disconnected
Reconnect the following connectors. Then perform a
conduction inspection. If there is no conduction, replace the
connector.
 Drum Unit – Drum Connection PCB connector
 Drum Connection PCB – Connect-Left PCB connector
 Connect-Left PCB – IOB connector
 Drum PCB defective
Replace the drum PCB.
 Connect-Left PCB defective
Replace the Connect-Left PCB.
 IOB defective
Replace the IOB.