Error Code: C-3912 Follow

Classification
Main body: Fusing temperature sensor/4 abnormality
 

Cause
Within a specified period of time after the warm-up starts, the temperature that the fusing temperature sensor/4 (TH4) detects does not reach 40°C However, the detection is not performed in the monochrome energy-save mode.
In the other case, it has not satisfied the Ready condition of TH4 within a specified period of time after the warm-up starts.
 

Measures to take when an alert occurs
The main body and the option stop immediately.
 

Estimated abnormal parts
• Fusing unit
• Printer control board (PRCB)
• AC drive board (ACDB)
• Fusing heater lamp/4 (L4)
• Fusing temperature sensor/4 (TH4)
• Thermostat/3 (TS3)
 

Correction

Solution
1. Check the connection between the rear side connector of the fusing unit and the main body side connector, and repair it when there is any abnormality.
2. Check the connector connection between TH4 and PRCB, and the wiring. Then repair it when there is any abnormality. (Wiring diagram: Main body (1/5): 10-H)
3. Check the connector connection between TS3 and ACDB, and the wiring. Then repair it when there is any abnormality. (Wiring diagram: Main body (1/5): 8-E)
4. Check the conduction of TS3, and repair it when there is any abnormality.
5. Check the installation condition of L4, and the activation or deactivation with the IO Check (45-00) and others. Then repair it when there is any abnormality. (Wiring diagram: Main body (1/5): 3-J)
Note
▪ The output check on the IO check mode has restrictive conditions. Check the IO check mode list before the output check.
6. Check the installation condition of TH4 and the temperature of the IO Check (45-16) and others, and adjust it when there is any abnormality. (Wiring diagram: Main body (1/5): 3-L)
7. Replace TH4.
8. Replace TS3.
9. Replace L4.
10. Replace ACDB.
11. Replace PRCB.