Ricoh M018 Service Manual page 185

Zero Cross Error
The zero cross signal is not detected for three seconds even though the fusing
lamp relay is on after turning on the main power or closing the front door.
Defective fusing lamp relay
547
1. Turn the main power switch off and on.
Execute "Engine Maintenance Menu" to recover the machine after
completing the recovery procedure. Otherwise, the machine continues to
issue this SC code and cannot be operated.
Low Temperature Error
The center thermistor detects 100°C or less for 4 seconds.
Defective fusing lamp
Defective thermistor
548
1. Replace the fusing unit.
2. Replace the fusing lamp.
Execute "Engine Maintenance Menu" to recover the machine after
completing the recovery procedure. Otherwise, the machine continues to
issue this SC code and cannot be operated.
SM Appendix 3-15
Service Call Conditions
M018/M019