Ricoh M040 Service Training page 135

New Detection Mechanism (Maintenance Kit)
Thermo-fuse
When the machine reaches operating temperature, new unit detection is performed.
After an "L' signal is detected, the fusing unit counter is cleared when the fusing
unit is replaced.
The thermo fuse opens after the fusing temperature reaches the target temperature.
The machine indicates "near end" when the fusing unit counter reaches 90 k, but
continues to operate.
Slide 135
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Fusing Unit - 7/7
Thermostat Thermostat Thermostat Thermostat
Fusing Fusing Fusing Fusing
control control control control
Circuit Circuit
Circuit Circuit
Heater
Triac
CPU New unit signal
Vcc
Fuse
Ｃ Ｃ Ｃ Ｃ
135
MD-P1b / M040 / C311N
MD-P1c / M041 / C312DN
Thermo fuse in the new
fusing unit opens when the
fusing temperature reaches
72 degrees centigrade.
Conditon Old New
H H H H L L L L
C C C C