Ricoh FT8680 Service Manual page 382

SYSTEM ERROR AND SERVICE CALL CONDITIONS
SC542 - Low Fusing Temperature
Definition:
The main PCB detects a low fusing temperature (fusing lower limit
temperature : 159°C/–17 169°C/–27) for more than 10 minutes.
NOTE: The Service Call message will be displayed at the first detection.
The main relay will be opened in this condition.
The fusing lower limit temperature can be changed by user tools
and service program mode.
Points to check
•
Fusing lamp
•
Fusing lamp control SSR
•
Main Relays (RA101 and 102)
•
Fusing thermistor
•
Interface PCB
SC543 - Fusing overheat
Definition:
The main PCB detects an extremely low resistance (< 500Ω/220°C) of the
fusing thermistor for more than 3 seconds.
NOTE: The service call message will be displayed at the first detection.
The main relays will be opened in this condition.
Points to check:
•
Fusing lamp control SSR
•
Fusing thermistor
•
Fusing lamp
•
Interface PCB
SC547 - Fusing Thermofuse Open
Definition:
Main PCB detects the fusing thermofuse open signal from the dc drive PCB
for more than 3 seconds.
NOTE: The service call message will be displayed at the first detection.
The main relays will be opened in this condition.
Points to check:
•
Thermofuse
•
DC drive PCB
6-20
31 July 1995