Samsung SCX-4100 Service Manual page 38

4.5.4 Fusing
The temperature of the heat roller's surface is detected according to the resistance value of the thermistor.
The thermistor resistance is measured using the A/D converter and thus the CPU can determine the temperature of
the heat roller. The AC power is controlled by comparing the target temperature to the value from the thermistor. If
the value from the thermistor is out of the controlling range while controlling the fusing process, the error stated in
the table occurs. (For the domestic model, the Q-PID method has been applied.)
• Heat Lamp Method
Error
Open heat error
Lower heat error
Over heat error
4.5.5 LSU
The LSU consists of the LD (Laser Diode) and the polygon motor control. When the printing signal occurs, the LD
is turned on and the polygon motor is enabled. When the light sensor detects the beam, Hsync occurs. When the
polygon motor speed becomes a normal, LReady occurs. If these two conditions are satisfied, the status bit of the
LSU controller register becomes 1 and the LSU is judged to be ready. If the two conditions are not satisfied, the
error shown in the table below occurs.
Error
Polygon motor error
Hsync error
Samsung Electronics
Description
When warming up, it has been lower
than 68°C over 28 seconds
• Standby:
It has been lower than 80°C over 10 seconds
• Printing:
- 2 consecutive pages: it has been lower than
145°C over 4 seconds.
- 3 consecutive page; it has been 25°C lower
than the fixed fusing temperature over 4 seconds.
It have been higher than 220°C over 3 seconds
When the polygon motor's speed doesn't
reach operating speed
The polygon motor's speed is normal,
but the Hsync signal is not created.
Description
Summary of product
LCD Displat
All open heat error are blinking
All low heat error are blinking
All over heat error are blinking
Service Manual
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