Service manual

2.2.1.3 Fusing Control
The thermistor detects the surface temperature of the fusing roller and inputs the corresponding
analog voltage to the PWB-A board. The heater lamp is turned ON and OFF by a signal output
from PWB-A, based on the temperature detected by the thermistor. A fusing error occurs if any of
following conditions is detected:
1. The thermistor voltage varies only in the range of 0.1 V within 12 to 30 seconds after the
upper fusing roller starts warming up.
2. 120 seconds has passed after the upper fusing roller started warming up. But the
temperature of the upper fusing roller is still under 190
o
C (374 F).
3. In standby, the upper fusing roller temperature drops under 140
o
C (284 F).
4. During printing, the upper fusing roller temperature drops under 150
o
C (302 F).
5. When the temperature is under control, the upper fusing roller temperature exceeds
240
oo
C (482 F).
CN4
CN13
4
5
2
Thermistor
Heater Lamp
Thermostat
Heater
ON/OFF
PWB-A Board
PWB-E Board
+5 V
CPU
Figure 2-12. Fuser Control
Operating Principles EPL-N2000 Service Manual
2-12 Rev.A