Ricoh SP 310DN, Service Manual, Page: 146 / 184

Service Call
M154/M155/M174/M175/A0A7/M287/M0BB 6-8 SM
544
High temperature error (hard)

During stand-by mode or a print job, the detected heating roller temperature
reaches 250°C.

Defective Main board

Defective PSU
1. Replace the Main board
2. Replace the PSU

Execute "Reset Fusing Unit SC" to recover the machine after completing
the recovery procedure. Otherwise, the machine continues to issue this
SC code and cannot be operated.
545
Fuser full heater error
The fuser full heater remained ON at full capacity for more than 9 s after the
fusing temperature attains reload temperature.

Deformed thermistor

Thermistor not in the correct position

Defective fusing lamp
1. Replace the fusing unit.
2. Replace the fusing lamp.

Execute "Reset Fusing Unit SC" to recover the machine after completing
the recovery procedure. Otherwise, the machine continues to issue this
SC code and cannot be operated.
547
Zero cross error

The zero cross signal is detected three times even though the fusing lamp
relay is off when turning on the main power.

The zero cross signal is not detected for 3 s econds even though the fusing
lamp relay is on after turning on the main power or closing the front door.

The detection error occurs twice or more in 10 zero cross signal detections.
This error is defined when the detected zero cross signal is less than 45.

The zero cross signal is not detected for 3 s econds while the main power
remains ON.