Ricoh M281 Series Service Manual page 473

SC No. Type
SC541-00 D
SM
Error Name/Error Condition/Major Cause/Solution
Fusing Thermistor (Center) Disconnected Error
Input from fusing thermistor (center) is 1019 or more (A/D value)
continuously for 4 seconds.

Connector pin defective

Triac defective

Fusing unit defective

Fusing thermistor connection PCB defective

IOB defective

Fusing thermistor (center) defective

Fusing thermostat defective

PSU defective

Connector pin defective
If the I/F connector pins of the fuser unit and the main unit
are deformed owing to foreign materials, replace the
connectors or the units including the connectors.

Triac defective
Disconnect the power cord and check that the resistance
between terminals T1 and T2 of the triac TRA31 and triac
TRA41 on the PSU are several Mega-Ohms and not
shorted. If failed, replace the PSU.
6-35
Service Call 501-582
D255/D256/M281/M282