In Ricoh’s proprietary Service Call (SC) code system, numbers are categorized by the component family. Codes in the 500 range specifically refer to issues with the fusing unit (also known as the fuser or fixing assembly).
SC569-00 translates to: "Fusing Thermistor Edge Malfunction (Center) – Zero Cross Error."
To break that down:
In practical terms: The printer’s main board sent power to the fuser lamp to heat up, but the thermistor reported a rate of temperature change or an absolute temperature that was physically impossible or dangerous. The printer shut down to prevent a fire hazard. sc569-00 ricoh
The fusing lamp provides heat. As it ages, its internal resistance changes, leading to erratic zero-cross signals. In some cases, the lamp may have a micro-crack that only fails when hot.
In sleeveless fuser designs, a seized pressure roller bearing can cause uneven mechanical load, indirectly affecting thermal regulation and triggering SC569.
For business-critical machines, individual component repair is risky. Replace the entire fuser unit with a genuine Ricoh OEM unit. After replacement: In Ricoh’s proprietary Service Call (SC) code system,
Paper dust, toner residue, or melted adhesive from envelope printing can coat the thermistor. A contaminated thermistor acts as an insulator, delaying temperature sensing. The fuser lamp overheats while the sensor reads “cold,” triggering a zero-cross error.
Contrary to simple software glitches, SC569-00 is almost always hardware-related. Here are the five most common triggers:
Warning: SP 5-810 resets counters. If you only want to clear the SC code without resetting PM (Preventive Maintenance) counters, use SP 7-403 (SC Code Reset) instead. In practical terms: The printer’s main board sent
The SC569-00 Ricoh error is a protective mechanism, not a random annoyance. It signals that your printer’s fusing system has detected a dangerous temperature anomaly at the roller edge. In 90% of cases, replacing the fusing unit and performing an engine clear resolves the issue.
However, ignoring the code or using improper reset methods can lead to catastrophic fuser meltdown, damaging pressure rollers, bearings, and even the printer’s plastic frame. Always diagnose the mechanical cause before resetting.
By understanding the relationship between the thermistor, zero-cross detection, and fuser sleeve integrity, you can return your Ricoh MFP to service quickly and prevent future SC569-00 shutdowns.
Need replacement parts? Always order the exact fuser assembly for your Ricoh model suffix (e.g., D147 4116 for MP 4055). Cross-reference your printer’s serial number with Ricoh’s parts catalog before purchasing.