Fuser failure detection
The DC controller determines a fuser unit failure, deactivates the FUSER HEATER CONTROL signal,
releases the relay to interrupt power supply to the fuser heater, and then notifies the formatter of a
failure state when it encounters the following conditions:
●
Abnormal temperature rise: The sleeve thermistor does not rise at a specified temperature within a
specified period after the fuser heater control starts.
●
Abnormally low temperature: The thermistors are at a specified temperature or lower during a
print operation or other fuser heating cycle.
●
Abnormally high temperature: The thermistors are at a specified temperature or higher, regardless
of the fuser control status.
●
Drive circuit abnormality: The frequency in the zerocross circuit is out of a specified range when
the product is turned on or is in the standby period.
18 Chapter 1 Theory of operation ENWW