Specifications

Samsung Electronics
Service Manual
System Overview
3-32
3) Fusing
The temperature change of the heat roller s surface is changed to the resistance value through the thermistor. By
converting the voltage value, which impressed to the resistance, to the digital value through the AD converter, the
temperature is decided. The AC power is controller by comparing the target temperature to the value from the thermistor.
If the value from the thermistor is out of controlling range while controlling the fusing, the error stated in the below table
occurs.
Open Heat Error
When the engine operates the warm-up process, if the temperature of the fixing unit is not higher than a specified
temperature, the engine defines Open Heat Error. When this error is broken out, the engine stops all functions and keeps
the error state. Also, the engine informs the error status of the main system. And then the error message is displayed at
LCD window or LED informing the error status of the user.
Low Heat Error
When the engine is at stand-by, printing or warm-up mode, if the temperature of the fixing unit is lower than the specified
temperature at each state and the lower temperature state is maintained during the specified time, the engine defines
Low Heat Error. When this error is broken out, the engine stops all functions and keeps it at the error state. Also the
engine informs the error status of the main system. And then the error message is displayed at LCD window or LED
informing the error status of the user.
Over Heat Error
For overall engine state, if the temperature of the fixing unit is higher than the specified temperature and the temperature
state is kept during the specified time, the engine defines Over Heat Error. When this error is broken out, the engine stops
all functions and keeps it at the error state. Also, the engine informs the error status of the main system. And then the
error message is displayed at LCD window or LED to inform the error status of the user.
* To recover the heat error: The heat error recovery is operated automatically when the error is only caused by Low Heat
Error, not the Heat Errors in Warm-up state and the Over Heat Error. If an error happens, then the engine memorizes a
present temperature. In case of Low Heat Error, the maximum heat is supplied to the fixing unit. When a specified time
is elapsed, the engine detects the temperature again. If the present temperature is higher than the memorized
temperature, the error is recovered. In case of Over Heat Error, no heat is supplied to the fixing unit. When a specified
time is elapsed, the engine detects a present temperature again. If the present temperature is a specified degree lower
than the memorized temperature, the error is recovered.