Error Messages and Codes 3-29
Fuser Sub Lamp Overheat Failure, Code 44
The front thermistor has detected an overheat condition.
Note
If this failure reoccurs three times successively, an Engine NVRAM value is set 
preventing further printer use until the Clear Tech Rep Fault (see pg. 6-20) is 
performed.
Troubleshooting References 
Applicable Parts Wiring and Plug/Jack Map References
■ Fuser
■ Engine Control Board
Troubleshooting Procedure 
Step Actions and Questions Yes No
1
1. Turn OFF power, remove the fuser 
assembly and allow it to cool down.
2. Measure the resistance between the 
Fuser connector P600-7 and P600-9.
3. Does the resistance measure between 
30 K and 190 K Ohms?
Go to step 2. Replace the fuser 
assembly.
2
1. Reinstall the fuser assembly.
2. Enter service diagnostics.
3. From the Sensor Tests run the Fuser 
Temperature test.
4. Is the temperature indicated 
approximately 165
o
C?
Go to step 4. Go to step 3.
3
1. Turn OFF printer power.
2. Measure the resistance between 
J641-4 and J641-5 on the engine 
control board.
3. Does the resistance measure between 
30 K and 190 K Ohms?
Go to step 4. Repair or replace 
the wiring 
harness.
4
1. Turn printer power back ON.
2. Is there ~+3.4 VDC between J590-3 
and ground?
Check the AC 
wiring harness to 
the fuser.
If the check is OK, 
replace the AC 
drive assembly.
Replace the 
engine control 
board.