Ricoh FT8680 Service Manual page 371

31 July 1995
SC302 - Charge Corona Leakage
Definition:
The charge power pack detects charge corona leakage and sends the leak
signal to the main PCB for more than 3 seconds.
NOTE: The dc power, 24 V (VP) and 38 V (VFL), will be cut at the same
time.
Points to check:
•
Charge corona unit
•
Charge corona power pack
•
Interface PCB
SC305 - Charge Corona Wire Cleaner Failure
Definition:
The main PCB detects a large current value for the charge corona wire
cleaner motor (mechanism lock) for more than 3 seconds when the cleaner is
activated.
NOTE: The cleaner moves back to its home position when the error
condition is reset.
Points to check:
•
Mechanical interference with the charge corona wire cleaner
•
Wire cleaner motor
•
Main PCB (motor drive circuit)
SC306 - Drum Potential Sensor Calibration Error
Definition:
During process control data initialization, the drum potential sensor output is
out of the adjustment range.
NOTE: After the system error reset, main PCB tries the calibration again.
If it fails again, the copier goes into the service call condition.
Points to check:
•
Drum potential sensor
•
Drum
•
Bias power pack
•
Drum current detection PCB
•
Main PCB (trigger signals to the bias power pack)
SYSTEM ERROR AND SERVICE CALL CONDITIONS
6-9