Ricoh G148, Service Manual

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The center thermistor (1) (not in direct contact with the hot roller) controls the temperature at the center of
the hot roller. The end thermistor (3) directly contacts the hot roller surface and prevents overheating. The
two thermostats (2) also prevent overheating.
The web cleaning unit (web roller, cleaning roller, and take up roller) applies a light coat of silicone oil to
the hot roller to prevent toner and paper dust from sticking to the hot roller.
The fusing exit sensor detects concertina jams at the fusing unit exit. This sensor is required because the user
may not see this type of jam in the machine when removing a jam at the exit.
The fusing unit and exit unit can be separated, making it easier to service.
Fusing Mechanism
The hot roller [A] and pressure roller [B] fuse the toner to the paper.
Two fusing lamps [C] (550 W) are inside the hot roller.
Two thermostats [D] are positioned above the hot roller near the center.
One thermistor [E] is also positioned above the hot roller near the center.
Another thermistor [F] is in contact with the end of the hot roller.
Thermistors
Center (non-contact) thermistor Temperature control
End (contact) thermistor Overheating protection
Thermostats*
1
Center (non-contact) thermostats Overheating protection
6. Details
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