C3722, C3725, C3726 (bizhub 4750i/4050i)

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Contents

Trouble typeC3722: Fusing abnormally high temperature detection (Edge of the heating roller)

C3725: Fusing abnormally high temperature detection (Main of the heating roller)

C3726: Fusing abnormally high temperature detection (Center of the heating roller)
RankA
Trouble detection conditionC3722: Detected temperature of the heating roller thermistor/Edg (TH1) goes beyond a given temperature for a given period of time consecutively.

C3725: Detected temperature of the heating roller temperature sensor (TEMS) goes beyond a given temperature for a given period of time consecutively.

C3726: Detected temperature of the heating roller thermistor/Ctr (TH2) goes beyond a given temperature for a given period of time consecutively.
Trouble isolation–
Relevant electrical parts-Fusing unit

-C3722: Heating roller thermistor/Edg (TH1)
-C3725: Heating roller temperature sensor (TEMS)
-C3726: Heating roller thermistor/Ctr (TH2)

-DC power supply (DCPS)
-CPU board (CPUB)
-Base board (BASEB)

Procedure

  1. Check the fusing unit for correct installation (whether it is secured in position).
  2. Check the open/close operation of the right door.
  3. Check the connector between the fusing unit-relay CN3-BASEB CN10E for proper connection and correct as necessary.
  4. Check the connector between the fusing unit-relay CN2-DCPS CN2 for proper connection and correct as necessary.
  5. Check CPUB for proper installation and correct as necessary.
  6. Replace the fusing unit. (Part# ACT8R70100)
  7. Replace CPUB. (Part# ACT9H01003)
  8. Replace BASEB.
    4750i (Part# ACT9H02013)
    4050i (Part# ACT9H02002)
  1. Replace DCPS. (Part# AAJRR70600)

(Link to the Field Service Manual)