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

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HP Enterprise CP5525 manual Fuser failure detection