Service manual

Product spec and feature
2-29
Service Manual
3) Transfer
The charging voltage, developing voltage and the transfer voltage are controlled by PWM (Pulse Width
Modulation). The each output voltage is changeable due to the PWM duty. The transfer voltage admitted
when the paper passes the transfer roller is decided by environment recognition. The resistance value of the
transfer roller is changed due to the surrounding environment or the environment of the set, and the voltage
value, which changes due to the environments, is changed through AD converter. The voltage value for
impressing to the transfer roller is decided by the changed value. Each voltage value is controlled according
to 3.3.4.2 Timing Chart.
4) 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.
5) Lamp Method
Error Description
OPEN HEAT ERROR
- When warming up, it has been lower than 90
ଇ over 45 seconds
LOW HEAT ERROR
- Standby
It has been lower than 130ଇ over 10 seconds
- Printing
After first page,
: It has been 30
ଇ lower than the fixed fusing temperature over 7 seconds.
OVER HEAT ERROR 1. It has been higher than 230ଇ over 3 seconds
2. It has been higher than 220ଇ over 20 seconds
3. It has been 10
ଇ higher than the fixed fusing temperature over 3 minutes.
6) LSU
The LSU is consisted of the LD (Laser Diode) and the polygon motor control. When the printing signal
occurs, it turns on the LD and drives the polygon motor. When the detector detects the beam, Hsync occurs.
When the polygon motor speed becomes strady, Lready occurs. If two conditions are satisfied, the status are
not satisfied, the error shown in below occurs
Error Type Description Remark
Polygon Motor Error Whenthe polygon motor speed doesn’t become steady Error display
Hsync Error The polygon motor speed is steady but the Hsync is not
generated
Error display