Dell 1600n - Multifunction Laser Printer B/W Service Manual page 42

4.5.4 Fusing
The temperature change of the heat roller's surface is changed to the resistance value through the thermis-
tor. By converting the voltage value to a digital value, through the AD converter, the temperature is decided.
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, the error stated in the table
occurs.
4.5.4.1 Error Type
Error
Open heat error When warming up, it has been lower than 68 °C over 25 sec
Lower heat error • Standby:
It has been lower than 100°C over 25 sec
• Printing:
- 2 consecutive pages: it has been lower than 145°C over 5 sec
- 3 consecutive page; it has been 40°C lower than the fixed fusing temperature over 4 seconds.
Over heat error It have been higher than 220°C over 3 seconds
4.5.5 LSU
The LSU is consists of the LD (Laser Diode) and the polygon motor control. When the printing signal occurs,
it turns the LD and drives the polygon motor. When the receiving light part detects the beam, Hsync occurs.
When the polygon motor speed becomes normal, LReady occurs. If the two conditions are satisfied, the sta-
tus bit of the LSU controller register becomes 1, the LSU is ready. If the two conditions are not satisfied, the
error shown in below occurs.
Error
Polygon motor error
Hsync error
Description
Description
When the polygon motor's speed doesn't become normal
The polygon motor's speed is normal, but the Hsync signal is not created.
Summary of Product
Service Manual
4-19