Error codes konica minolta

Code: C3903
Description:
Thermostat breaks detection. The motor lock signal remains HIGH for a predetermined continuous period of time while the motor is turning.
Causes:
• Fusing unit • Heating roller thermostat (TS1) • MFP board (MFPB)
Remedy:
1. Check the fusing unit for correct installation (whether it is secured in position). 2. Check the open/close operation of the upper right door. 3. Check the connector between the fusing unit-relay CN259-MFPB CN30E for proper connection and correct or change as necessary. 4. Replace the fusing unit. 5. Replace MFPB.