All codes
Service call
SC544
Fusing overheat (hardware)
AFusingCommon field call
Level A — stop, SP reset after repair
First check
Same as 543, but assume the heater drive is stuck on until proven otherwise.
What it means
Hardware over-temp (~250°C) latched by the thermistor / thermopile circuit. More serious than SC543.
Likely causes
- PSU triac shorted
- IOB
- Thermistor
On-site steps
Parts to have on the truck
- PSU
- IOB
- Fusing unit
SP / reset
SP5-810-001 after parts.
Related procedures
Related codes
Confirm the subcode and part number in the FSM for this serial. Raicoh is a field companion, not a replacement for the book.