Ricoh FT8680 Service Manual page 378

SYSTEM ERROR AND SERVICE CALL CONDITIONS
SC444 - No Drum Temperature Increase
Definition:
When the detected drum temperature is below 35°C, the main PCB cannot
detect within 3 minutes a temperature increase of more than 1°C.
NOTE: 1. The main relays will be opened in this condition.
2. No detection in copy mode.
Points to check:
•
Drum heater
•
Drum heater relays
•
Drum heater thermoswitches
•
Drum Thermistor
•
Main PCB (CN104-A4)
SC490 - Vacuum Fan Motor Overload
Definition:
The main PCB detects a lock signal from the vacuum fan for more than
3 seconds.
Points to check:
•
Vacuum fan
•
Interface PCB
SC491 - Optics Cooling Fan Motor Overload
Definition:
The main PCB detects a lock signal from the optics cooling fan for more than
3 seconds.
Points to check:
•
Optics cooling fan
•
Interface PCB
6-16
31 July 1995