Ricoh RN-MF1 Service Manual page 124

6. Troubleshooting
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 seconds 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 11 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 three times while the main power remains ON.
547
• Defective fusing relay
• Defective fusing relay circuit
• Shorted +24V fuse on the PSU
• Unstable power supply.
1. Check the power supply source.
2. Replace the +24V fuse on the PSU.
6
3. Replace the PSU
Zero cross frequency error
The zero cross signal is detected ten times while the fusing lamp relay remains ON after turning
on the main power.
• Defective fusing lamp relay
• Defective drive circuit of the fusing lamp relay
557
• Unstable input power source
1. Check the power supply source.
2. Replace the fusing unit.
• Execute "Fuser SC Reset" to recover the machine after completing the recovery procedure.
Otherwise, the machine continues to issue this SC code and cannot be operated.
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