Service manual

FrameMaker Ver.5.5E(PC) Di152/Di183 TROUBLESHOOTING
01.09.04
T- 2 9
C0520: Abnormally high fusing temperature
Step Check Result Action
4 Fusing Unit Interlock Switch (S2) is
operational.
<Check Procedure>
Check continuity across terminals
when the Fusing Unit Interlock
Switch (S2) is turned ON.
• Across S2-1A and S2-1B
• Across S2-2A and S2-2B
NO • Change Fusing Unit Interlock
Switch (S2).
YES • Change DC Power Supply (PU1).
5 Thermistor (TH1) is open-circuited.
<Check Procedure>
Check the resistance across CN15-2
and CN15-3 on the Fusing Unit side
with CN15 disconnected.
The Thermistor is open-circuited if
the resistance is infinity.
YES • Change Thermistor (TH1).
6 The following voltages are supplied
from the Master Board (copier: PWB-
A).
<Check Procedure>
Check voltage across a Master Board
(copier: PWB-A) pin and GND when
the Power Switch is turned ON.
• Voltage across PJ10A-7 and GND
DC24 V when Fusing Heater Lamp
(H1) is OFF
DC0 V when Fusing Heater Lamp
(H1) is ON
• Voltage across PJ10A-10 and
GND
DC24 V when Fusing Heater Lamp
(H1) is OFF
DC0 V when Fusing Heater Lamp
(H1) is ON
NO • Change Master Board (copier:
PWB-A).
Step Check Result Action
1 Thermistor (TH1) is dirty. YES • Clean Thermistor (TH1).
2 Thermistor (TH1) is open-circuited.
<Check Procedure>
Check the resistance across CN15-2
and CN15-3 on the Fusing Unit side
with CN15 disconnected.
The Thermistor is open-circuited if
the resistance is infinity.
YES • Change Thermistor (TH1).
NO • Change Master Board (copier:
PWB-A).